JUSTICE RAPP delivered the opinion of the court:

In this case involving business interruption insurance, ajury found that plaintiff, Lyon Metal Products, L.L.C. (Lyon), proved a businessinterruption loss of $400,000. Lyon appeals, contending (1) that the trial courterred in entering summary judgment in favor of defendant Protection MutualInsurance Company (Protection Mutual) on Lyon's claim pursuant to the IllinoisInsurance Code (Insurance Code) (215 ILCS 5/155 (West 1996)); (2) that the trialcourt erred in denying its motion in limine; (3) that the trialcourt erred in excluding evidence; (4) that the trial court erred in instructingthe jury; (5) that the jury's verdict was against

the manifest weight of the evidence; and (6) that the trialcourt erred in denying prejudgment interest. We affirm.

I. FACTS

Lyon manufactures various steel workplace products including shelving,storage racks, ergonomic furniture, cabinets, lockers, and other miscellaneousitems. Lyon has its principal manufacturing and distribution facility in Aurora,Illinois. Lyon also sells and distributes certain products it does notmanufacture, referred to as pass-through items.

Lyon was insured by Protection Mutual under an "all risk" insurancepolicy providing various coverages, including property damage, for a premium of$112,000 per year. Protection Mutual also provided Lyon with additional coverageagainst business interruption for a premium of $39,499 per year.

On July 17 to 18, 1996, flooding caused extensive damage to Lyon's Aurorafacility. As a result of the flood, Lyon was prevented from producing goods andcontinuing business operations for 22 consecutive days, including 17 productiondays.

Protection Mutual compensated Lyon in the amount of $7,878,836 for propertydamage, which included the regular cash selling price of $3,773,250 for thedamaged finished goods in inventory. Protection Mutual also paid Lyon $281,724pursuant to the business interruption endorsement for the expenses Lyon incurredto reduce its loss and make up lost production. Lyon made further claim forbusiness interruption loss in the amount of $5,009,105. Protection Mutualdisagreed with Lyon's calculation of its business interruption loss.

Lyon filed a complaint against Protection Mutual alleging breach of contractand a cause of action pursuant to section 155 of the Insurance Code (215 ILCS5/155 (West 1996)) for alleged vexatious and unreasonable delay in payment. Lyonalleged that it tendered to Protection Mutual a $5,009,105 claim for the actualloss sustained and expenses covered under the business interruption endorsementof the policy. Lyon further alleged that Protection Mutual refused to pay theclaim. Subsequently, Lyon amended the complaint, adding a count pursuant to theIllinois Interest Act (815 ILCS 205/0.01 et seq. (West 1996)) forprejudgment interest on the amount Protection Mutual failed to pay. ProtectionMutual denied Lyon's allegations, contending that the amount Protection Mutualpaid Lyon for its damaged inventory must be considered when calculating Lyon'sactual loss sustained under the business interruption endorsement.

Protection Mutual filed a motion for partial summary judgment (735 ILCS5/2--1005 (West 1996)) on the breach of contract claim, requestinginterpretation and application of the business interruption endorsement of thepolicy. Protection Mutual also filed a motion for summary judgment on Lyon'sInsurance Code claim. Protection Mutual argued that it was entitled to partialsummary judgment on the breach of contract count because, although the amount ofthe business interruption loss is a factual issue in dispute, the legal issue ofProtection Mutual's entitlement to a credit against the business interruptionloss should be decided by the court as a matter of law. Protection Mutualcontended that the court should rule that the fact that it paid Lyon the regularcash selling price for Lyon's damaged inventory decreased or eliminated Lyon'sbusiness interruption loss because Protection Mutual became Lyon's customer andprevented Lyon from suffering lost earnings from lost sales during the period ofinterruption. In response, Lyon argued that it suffered independent losses dueto property damage and business interruption and should be compensated for bothlosses. The trial court denied Protection Mutual's motion for partial summaryjudgment. In ruling on this motion, the court stated:

"Let me just rule on this part of it. I have read this, reread it, and intend to reread it again. It's neither clear nor free from doubt in my mind that the insurance company, Protection Mutual, the defendant in this case, is entitled to a credit.

However, this is not to be construed as a ruling with respect to whether or not the existence of the six weeks inventory affects the calculation of the appropriate recovery under the business interruption endorsement, and I am not prepared to say that at this point.

I think there are genuine issues on the trier of fact that need to be resolved on this issue as I perceive it to be at this juncture; and so the motion for summary determination of this issue is going to be denied."

The trial court granted Protection Mutual's motion for summary judgment onLyon's claim under the Insurance Code.

Prior to trial, Lyon filed a motion in limine seeking theexclusion of evidence related to a setoff or credit based upon payments made byProtection Mutual to Lyon for property damage, claiming that the policy containsno language providing for such a setoff or credit. In denying this motion, thecourt stated:

"[T]he issue in this case is actual loss sustained during the period of interruption in terms of net profit which is prevented from being earned due to the interruption and fixed charges to the extent only that such charges would have been earned had no interruption of production or suspension of business operations occurred.

These motions will be denied, insofar as granting them would preclude any testimony with respect to the effect, if any, of payment for inventory under the property endorsement on the calculation *** of actual loss sustained under the business endorsement provisions of this policy."

At trial, Lyon called its chief executive officer, Robert Washington.Washington said that Lyon was prevented from producing goods and from continuingbusiness operations during the period of interruption. Lyon received $3,700,000from Protection Mutual for the inventory that was damaged in the flood. Lyonnever sold its damaged inventory to Protection Mutual, and the $3,700,000 wasnot booked as a sale.

Washington estimated that Lyon would have produced 300,000 pounds of goodsper day and would have done 100,000 pounds of pass-through business per day forthe 17-day period of business interruption. The goods have a sales value ofapproximately $1.30 per pound. The sales volume of the produced goods and thepass-through goods for the 17-day period is approximately $8,800,000. Washingtonreduced that number by the variable charges, which are about 50% of the salesvolume, and calculated a figure of $4,400,000 in lost net profit and fixedcharges.

According to Washington, Lyon also received a total of $281,000 fromProtection Mutual for expenses to reduce the loss. Lyon was able to put itsinventory back to preflood levels by sometime in November or December 1996.

Lyon's next witness was Douglas Harrison, vice-president of finance for Lyon.Harrison prepared a claim for Lyon's loss due to business interruption andsubmitted it to Protection Mutual. According to Harrison, Lyon's projected salesfor the period of business interruption were $4,074,450 based on the actualsales reached by Lyon in June 1996. According to Harrison's claim, the totallost net profit and fixed charges earned for the period of business interruptionwere $4,413,506. Harrison's claim also included various expenses Lyon incurredin reducing its loss and replenishing its inventory for a total businessinterruption claim of $5,009,105. Harrison acknowledged that Protection Mutualpaid $281,724 of Lyon's expense in reducing loss.

Harrison indicated that Lyon was paid roughly $3,700,000 for damagedinventory, and that amount was listed as an extraordinary item on Lyon'sfinancial statement rather than as a receivable. The $3,700,000 was not includedin the $95 million in sales for 1996. Lyon employees worked overtime in August,September, and October 1996 to replenish the inventory. The overtime pay wasamong the expenses Lyon incurred to reduce loss and replenish inventory and wasincluded in the claim Harrison prepared.

Protection Mutual called Judith Spry, certified public accountant, whoperformed an analysis of Lyon's actual loss sustained from businessinterruption. According to Spry, the first step in calculating a businessinterruption loss is to project sales. Every sales dollar is made up of variablecharges, fixed charges, and net profit. The actual loss sustained is the amountof net profit and fixed charges that can be allocated to the lost sales.Variable costs are not part of the equation because those costs do not continueduring a period of interruption.

To determine the projected sales, Spry used the first six months of 1996. Forthat six-month period, the average net profit and fixed charges as a percentageof sales were 40.25%. Spry calculated projected sales of $2,783,808 for theperiod of business interruption. Spry then took into account the sale of theinventory to Protection Mutual for $3,773,250, which eliminated lost sales forthe period of business interruption because that amount exceeded projected salesfor the period of business interruption. Spry explained that Lyon made its netprofit and fixed charges for the period of business interruption from the saleof the damaged inventory to Protection Mutual. According to Spry, there is nodistinction between Protection Mutual paying the regular selling price forLyon's damaged inventory and a customer purchasing that inventory at the sellingprice.

Protection Mutual also called John A. Damico, certified public accountant.Damico explained that net profit is what is left after subtracting fixed chargesand variable charges from sales. According to Damico, the business interruptionendorsement of the policy says that the insured is entitled to recover the netprofit and the fixed charges that the insured could not earn due to theinterruption of business. Damico explained that, if there was a reduction insales that was attributable to the flood, then Lyon would be compensated for thenet profit and fixed charges attributable to those sales. In determining thesales that Lyon would have enjoyed had there been no flood, Damico looked atmonthly sales for 1995 and 1996.

Damico learned that Protection Mutual paid Lyon the regular cash sellingprice of about $3,700,000 for Lyon's damaged inventory. Damico considered the$3,700,000 an actual sale that should be subtracted from the projected sales forthe period of business interruption. According to Damico, the fact that Lyon wascompensated for the damaged inventory allowed Lyon to earn net profit and fixedcharges attributable to those finished goods.

Damico calculated Lyon's projected lost sales for the period of interruptionat $2,783,808 to $2,819,809. According to Damico, 41.62% of every sales dollarLyon made consists of fixed charges and net profit. Damico calculated Lyon'slost net profit and fixed charges by multiplying the projected sales numbers by41.62% and arriving at a result of $1,158,621 to $1,173,605.

Next, Damico credited the lost net profit and fixed charges with the netprofit and fixed charges earned by Lyon as a result of the compensation Lyonreceived for the damaged inventory. The net profit and fixed chargesattributable to the $3,773,250 in compensation for the inventory are $1,570,427.When Damico subtracted the $1,570,427 from the lost net profit and fixedcharges, he arrived at zero lost profit and fixed charges or, put another way,zero actual loss sustained. According to Damico, Lyon recovered $1,570,427 innet profit and fixed charges when it was compensated for the damaged inventory,and that amount exceeded the net profit and fixed charges Lyon would have earnedhad there been no flood.

After the evidence was closed, Protection Mutual made a motion for a directedverdict requesting the trial court to direct the jury to include the payment of$3,773,250 for the damaged inventory in actual sales when calculating Lyon'sbusiness interruption loss. The trial court denied the motion.

The jury returned a verdict in favor of Lyon and against Protection Mutual.The jury found that Lyon proved a business interruption loss according to theterms of the insurance policy in the sum of $400,000. The trial court enteredjudgment on the verdict. The trial court denied Lyon's posttrial motion andmotion for prejudgment interest. Lyon timely appealed.

II. DISCUSSION

A. SUMMARY JUDGMENT ON LYON'S INSURANCE CODE CLAIM

Lyon contends that the trial court erred in granting summary judgment infavor of Protection Mutual on Lyon's Insurance Code claim. Specifically, Lyoncontends that Protection Mutual's conduct has been vexatious and unreasonable asa matter of law or, alternatively, there were genuine issues of material fact asto whether Protection Mutual's failure to pay Lyon's claim was vexatious andunreasonable. Protection Mutual contends that the trial court properly grantedsummary judgment because Lyon produced no evidence to establish a factual basisfor the unreasonableness of Protection Mutual's position.

Summary judgment is proper only where the pleadings, depositions, andadmissions on file, together with the affidavits, if any, show that no genuineissue as to any material fact exists and that the movant is entitled to judgmentas a matter of law. 735 ILCS 5/2--1005(c) (West 1998). In ruling on the motion,the court is required to construe all evidentiary material strictly against themovant and liberally in favor of the nonmovant. Laurel Motors, Inc. v.Airways Transportation Group of Cos., 284 Ill. App. 3d 312, 316 (1996).While the nonmoving party in a summary judgment motion is not required to provehis case, he must nonetheless present a factual basis that would arguablyentitle him to a judgment. Gauthier v. Westfall, 266 Ill. App. 3d 213,219 (1994). If from the pleadings, depositions, affidavits, and admissions onfile, a plaintiff fails to establish an element of his cause of action, summaryjudgment for the defendant is proper. Pyne v. Witmer, 129 Ill. 2d 351,358 (1989). The propriety of an order granting summary judgment is a question oflaw we review de novo. Laurel Motors, Inc., 284 Ill. App.3d at 316.

Section 155 of the Insurance Code provides an extracontractual remedy topolicyholders whose insurer refuses to recognize liability or pay a claim undera valid insurance policy in a vexatious and unreasonable manner. Cramer v.Insurance Exchange Agency, 174 Ill. 2d 513, 520 (1996). Section 155(1)provides:

"(1) In any action by or against a company wherein there is in issue the liability of a company on a policy or policies of insurance or the amount of the loss payable thereunder, or for an unreasonable delay in settling a claim, and it appears to the court that such action or delay is vexatious and unreasonable, the court may allow as part of the taxable costs in the action reasonable attorney fees, other costs, plus an amount not to exceed any one of the following amounts:

(a) 25 % of the amount which the court or jury finds such party is entitled to recover against the company, exclusive of all costs;

                          (b) $25,000;

(c) the excess of the amount which the court or jury finds such party is entitled to recover, exclusive of costs, over the amount, if any, which the company offered to pay in settlement of the claim prior to the action." 215 ILCS 5/155(1) (West 1996).

However, if there is a bona fide dispute about the coverage,delay in settling the claim does not violate the statute. Green v.International Insurance Co., 238 Ill. App. 3d 929, 935 (1992).

Lyon alleged in its complaint that the failure and refusal of ProtectionMutual to pay the claim were vexatious and unreasonable such that Lyon isentitled to fees, costs, and penalties pursuant to the statute. In its motionfor summary judgment, Protection Mutual raised a bona fide disputeregarding the calculation of the actual loss sustained pursuant to the businessinterruption endorsement, namely, whether the $3,700,000 in compensation for thedamaged inventory should be considered in calculating actual loss sustained.Protection Mutual pointed to language in the business interruption endorsementand to case law supporting its position. Furthermore, nothing in the pleadings,depositions, affidavits, or admissions rebuts Protection Mutual's assertion thatthere was a bona fide dispute as to the coverage under thebusiness interruption endorsement. Accordingly, there was no factual basis thatwould arguably entitle Lyon to a judgment on this claim. Therefore, the trialcourt did not err in granting summary judgment for Protection Mutual on theInsurance Code claim.

B. MOTION IN LIMINE

On appeal, Lyon contends that the trial court erred in denying its motion inlimine that sought the exclusion of evidence of a setoff or creditagainst Lyon's business interruption loss based upon the payment for the damagedinventory. Lyon argues that the trial court should have ruled as a matter of lawthat the insurance policy does not allow Protection Mutual to reduce Lyon'sbusiness interruption loss by the payment for damaged inventory. Lyon now urgesthis court to make that ruling and remand the cause for a new trial.

Initially, Protection Mutual argues that Lyon has waived this issue on appealbecause Lyon did not raise it in its posttrial motion. We disagree. Lyonspecifically states in its posttrial motion that the amount recoverable by Lyonunder the business interruption endorsement is to be computed based upon Lyon'sloss of production and not lost earnings. A posttrial motion need not specifyerrors in detail; the motion need only indicate the grounds upon which themovant relies with sufficient particularity to afford the trial court theidentity of the error relied upon. Wilson v. Clark, 80 Ill. App. 3d 194,198 (1980). The trial court was aware of Lyon's specific objection to admittingevidence of a setoff or credit against the amount due under the businessinterruption endorsement for payments to compensate Lyon for its damagedinventory. Therefore, Lyon has not waived this issue on appeal.

The trial court was asked numerous times during this case to rule on whetherthe payment for the damaged inventory should be considered in calculating Lyon'sbusiness interruption loss but did not do so. Instead, the trial courtcharacterized the issue as one of fact for the jury to consider. Essentially thetrial court ruled that the compensation for the damaged inventory could beincluded in the calculation if the jury so chose.

We agree that this is an issue of law that should have been determined by thetrial court prior to trial. Legal questions of the construction of an insurancepolicy, and the parties' rights and obligations thereunder, rest exclusivelywith the trial court. Chester v. State Farm Mutual Automobile Insurance Co.,227 Ill. App. 3d 320, 325-26 (1992). "When facts are undisputed, thequestion of whether those facts fall within the provisions of an insurancepolicy is a matter of interpretation, the province of the court rather than thefact finder." United Farm Bureau Mutual Insurance Co. v. Elder, 86Ill. 2d 339, 342-43 (1981). The construction of an insurance policy is aquestion of law subject to de novo review. American StatesInsurance Co. v. Koloms, 177 Ill. 2d 473, 479-80 (1997).

Lyon directs us to Kus v. Sherman Hospital, 268 Ill. App. 3d 771, 782(1995), where this court held that permitting a jury to determine a legal issuerequires reversal when plaintiff is deprived of a fair trial. Lyon contends thatKus requires reversal of this jury's verdict. We do not agree.

This court can make an independent determination of a question of law (BowersManufacturing Co. v. Chicago Machine Tool Co., 117 Ill. App. 3d 226, 232(1983)), and, for the reasons that follow, we conclude that the payment fordamaged inventory must be considered in calculating Lyon's business interruptionloss. Accordingly, allowing the jury to include the damaged inventory payment inthe calculation if it saw fit, when the jury should have been instructed that itmust include the payment, did not deprive Lyon of a fair trial.

Protection Mutual's position is that Lyon sold the damaged inventory to it,thereby eliminating lost sales (including the component net profit and fixedcharges) during the period of business interruption. Lyon argues that there isno language in the insurance policy that supports Protection Mutual's positionor that specifically states "Protection Mutual will credit or reduce theamount of business interruption liability by the amounts paid for finished goodsinventory at the cash selling price."

We believe that the language defining "actual loss sustained" underthe business interruption endorsement of the policy requires that thecompensation for the damaged inventory be considered in calculating actual losssustained. The policy reads, in pertinent part, as follows:

"BUSINESS INTERRUPTION ENDORSEMENT

In consideration of additional premium, this Policy is extended to cover the Actual Loss Sustained by the insured during a Period of Interruption directly resulting from physical loss or damage of the type insured against by this Policy, to property not otherwise excluded by this Policy, utilized by the insured and located as described elsewhere in this policy.

In the event the Insured is wholly or partially prevented from producing goods or from continuing business operations or services and is unable:

(a) to make up lost production within a reasonable period of time (not to be limited to the period during which production is interrupted), or

(b) to continue business operations or services, all through the use of any property or service owned or controlled by the Insured, or obtainable from any other sources, whether the property or service is at a location specified herein or through working extra time or overtime at the location(s) specified herein or at any other location, including any other location(s) acquired for the purpose, then this Company shall be liable, subject to all other conditions of this Policy not inconsistent herewith, for the Actual Loss Sustained of the following items during the Period of Interruption:

Item No. 1     (A) NET PROFIT, before deducting income
                        taxes, which is prevented from being earned due to
                        the interruption of production or suspension of 
                        business operations or services;
                    (B) FIXED CHARGES ***, to the extent only that
                       such charges would have been earned had no 
                       interruption of production or suspension of business
                       operations or services occurred.  ***

EXPENSES

Expenses, over and above normal operating expenses, necessarily incurred by the Insured in making up lost production or in reducing loss otherwise payable under this Endorsement are covered hereunder, but in no event shall this Company be liable for an amount greater than that for which it would have been liable had the insured been unable to make up any lost production or to continue any business operations or services."

The language is clear and unambiguous so that the meaning of the contract canbe discerned; accordingly, we must give effect to that meaning. See Grevas v.United States Fidelity & Guaranty Co., 152 Ill. 2d 407, 410 (1992).Clearly, the endorsement states that if the insured is able to continue itsbusiness operations, namely, selling metal workplace products, through the useof any of its property, including the damaged inventory, then the insured isrequired to do so. Under the terms of the business interruption endorsement,Protection Mutual is liable for the actual loss sustained in net profit that isprevented from being earned due to the interruption as well as the fixed chargesthat would have been earned had no interruption occurred. If no sales areprevented by the interruption, net profit and fixed charges will be earned.Accordingly, if there is enough inventory to meet the projected sales for theperiod of interruption there is no loss of earnings.

A review of pertinent case law supports our conclusion. "The generalpurpose of business interruption insurance is to protect the earnings which theinsured would have enjoyed had no interruption occurred." A. Miller& Co. v. Cincinnati Insurance Co., 217 Ill. App. 3d 572, 576 (1991). Seealso Archer-Daniels-Midland Co. v. Phoenix Assurance Co., 975 F. Supp.1124, 1127 (S.D. Ill. 1997) ("Business Interruption insurance protectsearnings that are lost or diminished because of business interruption"). Innumerous cases it has been stated, and we think correctly, that when there is aloss of production capacity without a loss of earnings there is no recoverablebusiness interruption except the extra expense necessary to prevent loss ofearnings. National Union Fire Insurance Co. v. Anderson-Pritchard Oil Corp.,141 F.2d 443, 445 (10th Cir. 1944); Northwestern States Portland Cement Co.v. Hartford Fire Insurance Co., 360 F.2d 531, 533 (8th Cir. 1966); MetalMastersof Minneapolis, Inc. v. Liberty Mutual Insurance Co., 461 N.W.2d 496 (Minn.App. 1990).

We find Portland Cement to be instructive on this point. In PortlandCement a fire rendered one of the insured's two cement manufacturing plantsincapable of producing clinker, an ingredient in cement. The insured wastherefore required to use its older, less efficient plant to produce clinker. PortlandCement, 360 F.2d at 532. The insured did not suffer any loss of sales due tothe interruption because it had a large inventory of finished cement andstockpiled clinker to meet customer demands. Portland Cement, 360 F.2d at532-33.

The insured contended that its business interruption policy entitled it tothe value of the clinker it would have produced had there not been a fire. Theinsured asserted that as a result of the fire it lost production, not sales, andthat under the language of the policy both production and sales are insured. Theinsurer contended that the insured was entitled only to the expense in excess ofnormal incurred in replacing the finished stock of cement that was sold toreduce the loss. Portland Cement, 360 F.2d at 533.

The Portland Cement court agreed with the insurer and found that thepolicy was designed to insure against loss of earnings and, in the absence ofloss of earnings, liability was limited to the extra expense necessary toprevent the loss of earnings. Portland Cement, 360 F.2d at 533. The PortlandCement court stated:

" 'This policy covers only against loss resulting directly from necessary interruption of business, caused by damage to or destruction of real or personal property, except finished stock.' It is readily apparent, as we will endeavor to explain, that the loss mentioned is actual loss of earnings resulting from the interruption of the insured's business caused by the perils insured against. That this is so is consistent with the basic object for which such a business is ordinarily conducted, viz., to realize earnings from the operation of business." Portland Cement, 360 F.2d at 533.

Lyon points out that Portland Cement does not address whether theinsurer can reduce the amount due under the business interruption coverage bythe compensation paid by the insurer for damaged inventory under property damagecoverage. We fail to see how the source of the earnings due to sales changes thecalculation of actual loss sustained under the policy. The result is the samewhether the inventory was sold to customers during the period of interruption orthe insured received the same amount of compensation for the damaged inventoryunder a policy of insurance, namely, no loss of earnings from the loss of salesduring the period of business interruption.

Lyon argues that the compensation for the damaged inventory under theproperty damage portion of the insurance policy is not a sale as defined in FoxfieldRealty, Inc. v. Kubala, 287 Ill. App. 3d 519, 524 (1997), citing Black's LawDictionary 1337 (6th ed. 1990), because the title did not transfer to ProtectionMutual nor did Protection Mutual take actual possession of the damagedinventory. Lyon contends that, because there was no sale of the damaged goodsinventory, the $3,773,250 cannot be included in the calculation of actual losssustained. We disagree.

For the purpose of this analysis, there is no distinction between Lyon'sselling its damaged inventory to a customer in the ordinary fashion and Lyon'sreceiving the regular cash selling price for the same inventory under the termsof an insurance policy. Whether a "sale" took place is not crucial.The gravamen of the analysis is whether the compensation for the damagedinventory allowed Lyon to earn net profit and fixed charges in the same way Lyonwould have earned net profit and fixed charges had there been no flood and theinventory was sold in the ordinary manner.

Lyon also makes the argument that it paid an additional premium for theadditional business interruption coverage and, therefore, Lyon had two separatecoverages and suffered two separate losses. Accordingly, Lyon argues, it shouldbe compensated for its loss of production as well as its damaged inventory. Lyoncontends that under Protection Mutual's theory either the additional businessinterruption coverage was illusory or Lyon did not get the value of the propertydamage coverage. We do not agree.

Lyon's argument underscores its misunderstanding of the business interruptioncoverage it purchased. The business interruption endorsement covers a loss ofearnings due to a loss of production, not just a loss of production. See PortlandCement, 360 F.2d at 533. Lyon was compensated for the damaged finished goodsunder the property damage portion of the policy and for the expenses it incurredin reducing its loss under the business interruption endorsement. Additionally,the jury in this case apparently concluded that Lyon's damaged inventory was notsufficient to cover the projected sales for the period of interruption anddetermined that Protection Mutual owed Lyon $400,000 for the net profit andfixed charges attributable to projected sales in excess of the $3,773,250 incompensation for damaged inventory. That $400,000 was in addition to thecompensation for the damaged finished goods. Accordingly, Protection Mutual wasrequired to pay Lyon under both types of coverage.

Moreover, business interruption insurance, like all insurance, should comportwith Illinois public policy indemnifying the insured for the loss but notproviding a windfall profit. Cohen Furniture Co. v. St. Paul Insurance Co.,214 Ill. App. 3d 408, 415 (1991). If Lyon were allowed to recover for thedamaged inventory, the lost production during the period of interruption, andthe expenses incurred in replenishing its inventory, it would recover twice forthe net profit and fixed charges attributable to the damaged inventory.

We find no merit in Lyon's alternative argument that, at best, ProtectionMutual's position reflects an ambiguity in the policy that must be resolved infavor of Lyon. The record reveals that at no time did ether party suggest to thetrial court that the policy was ambiguous, nor have we found any ambiguity.

For the foregoing reasons, we hold that the policy requires that thecompensation paid to Lyon for damaged inventory must be considered incalculating Lyon's actual loss sustained as defined by the business interruptionendorsement to the insurance policy. Accordingly, the trial court did not err indenying Lyon's motion in limine requesting the exclusion ofevidence of compensation for the damaged inventory to prove actual losssustained.

C. EXCLUSION OF 3201 ENDORSEMENT

Lyon' next argument on appeal is that the trial court erred in prohibitingLyon from admitting Protection Mutual's 3201 endorsement. The 3201 endorsementprovides:

"In determining net sales in the event of loss hereunder at mercantile or nonmanufacturing operations, any amount recovered under the property damage policies for loss or damage to or destruction of merchandise shall be included as though the merchandise had been sold to the insured's regular customers."

Although this endorsement was not included in the policy sold to Lyon, Lyonbelieves that it was relevant to show that when Protection Mutual intends totake a credit against the business interruption loss for property damagepayments made to the insured it knows how to do so. Protection Mutual respondsthat such evidence was irrelevant to the issue of the calculation of Lyon'sactual loss sustained under the business interruption endorsement of thisinsurance policy. We agree with Protection Mutual.

The exclusion or the admission of evidence rests within the sound discretionof the trial court and will not be reversed absent an abuse of discretion. Leonardiv. Loyola University, 168 Ill. 2d 83, 92 (1995). The 3201 endorsement wasnot relevant to the calculation issue because neither party has suggested nor dowe find that the insurance policy was ambiguous. Extrinsic evidence isinadmissible to contradict the terms of an unambiguous contract. MissouriPacific R.R. Co. v. American Re-Insurance Co., 286 Ill. App. 3d 129, 139(1996). Accordingly, the trial court did not err in excluding the 3201endorsement from evidence.

D. JURY INSTRUCTION

Lyon contends that the trial court erred in charging the jury with thefollowing instruction submitted by Protection Mutual:

"Business interruption insurance is designated to do for the business what the business would have done for itself had no loss occurred."

Lyon argues that this instruction unduly emphasizes an abstract principlethat is not directly in issue. We do not agree.

The instruction is an accurate statement of the law. See National UnionFire Insurance Co., 141 F.2d at 445. Having concluded as a matter of lawthat the insurance policy requires that the compensation paid for Lyon's damagedinventory be included in the calculation of the actual loss sustained, the courtwould have been correct to so instruct the jury. A judgment will not be reversedon the basis of faulty jury instructions unless a party can show prejudice as aresult. Bender v. Consolidated Mink Ranch, Inc., 110 Ill. App. 3d 207,215 (1982). If the instruction is at all faulty, it is in Lyon's favor;therefore, Lyon has not demonstrated prejudice, and reversal is not required.

E. MANIFEST WEIGHT OF THE EVIDENCE

Lyon's next contention on appeal is that the jury's verdict is against themanifest weight of the evidence. Lyon argues that the verdict is not supportedby the evidence whether the jury considered the $3,700,000 payment for thedamaged inventory or not. Lyon contends that, if the jury did consider thepayment, the evidence does not support the verdict because Protection Mutual'sexperts testified that Lyon's actual loss sustained was at least $1,100,000 ifthe $3,700,000 payment is not included in the calculation. On the other hand,Lyon contends that, if the jury did consider the payment, the $400,000 verdictis not supported by the evidence because as a matter of law the insurance policydoes not provide for including this payment in calculating actual loss sustainedand there is no evidentiary basis to do so because the $3,700,000 payment wasnot a sale.

In response, Protection Mutual asserts that Lyon has waived this issuebecause Lyon insisted on a general verdict form and objected to the specialverdict forms prepared by Protection Mutual, which would have alleviated theuncertainty as to the method of calculation performed by the jury. ProtectionMutual therefore argues that Lyon cannot seek relief from error that Lyon hascaused to be injected into the proceedings.

We believe a verdict form with special interrogatories would have beenappropriate in this case. However, the error Lyon assigns is that the jury'sgeneral verdict of $400,000 is against the manifest weight of the evidence, notthat the trial court erred in rejecting a special verdict form in favor of ageneral verdict form. Accordingly, we will consider the merits of Lyon'sargument.

A jury's verdict will not be set aside unless the verdict was contrary to themanifest weight of the evidence. Niewold v. Fry, 306 Ill. App. 3d 735,747 (1999). In determining whether a jury's verdict is against the manifestweight of the evidence, the evidence must be examined in a light most favorableto the appellee. Niewold, 306 Ill. App. 3d at 747. A verdict is againstthe manifest weight of the evidence only when an opposite conclusion is clearlyapparent or when the verdict appears to be arbitrary or to be unsupported by theevidence. Niewold, 306 Ill. App. 3d at 747.

The jury determined that Lyon proved a business interruption loss accordingto the terms of the insurance policy in the amount of $400,000. We need notconsider the scenario where the jury did not consider the $3,700,000 paymentbecause (1) we have rejected the arguments Lyon asserts in support of the jury'sverdict being against the manifest weight of the evidence under that scenario;and (2) the evidence supports the verdict if the jury did consider that payment.We will not disturb the jury's verdict unless we are able to say that there isno evidence that fairly tends to support the verdict. See Gilman v. Kessler,192 Ill. App. 3d 630, 639 (1989).

The evidence presented at trial consisted of the following estimated figures:

The jury reasonably could have arrived at the approximate figure of$4,500,000 in projected sales for the period of interruption, considering thatthe estimates ranged from $8,800,000 to $2,783,808. If the jury subtractedroughly $3,700,000 in actual sales from $4,500,000 in projected sales, it wouldarrive at $800,000 in lost sales for the period of business interruption. If thejury believed Washington's estimate that net profit and fixed charges are 50% ofeach sales dollar, then the jury would have multiplied the $800,000 in lostsales by .50 and arrived at $400,000 in actual loss sustained under the businessinterruption endorsement of the policy. A verdict falling within the flexiblerange of conclusions that reasonably can be supported by the facts will beupheld on appeal. Best v. Taylor Machine Works, 179 Ill. 2d 367, 412(1997).

Lyon also contends that the jury's verdict is against the manifest weight ofthe evidence because Lyon proved fixed charges in excess of $2 million that arespecifically covered in the definition of actual loss sustained. Lyon contendsfurther that Protection Mutual's property damage payment has nothing to do withthe fixed charges incurred during the period of interruption. We disagree.

The evidence established that every sales dollar is made up of variablecharges, fixed charges, and net profit. Therefore, when Lyon was reimbursed forthe damaged inventory, it earned the fixed charges attributable to the$3,773,250. Also, a percentage of the $400,000 verdict presumably representsfixed charges owed to Lyon.

After examining the evidence in this case in a light most favorable toProtection Mutual, we cannot say that the jury's verdict was against themanifest weight of the evidence.

F. PREJUDGMENT INTEREST

Finally, Lyon contends that the trial court should have granted its requestfor prejudgment interest. We disagree.

Whether to award prejudgment interest is a matter within the trial court'ssound discretion, and its decision will not be disturbed on appeal absent anabuse of discretion. Marcheschi v. Illinois Farmers Insurance Co., 298Ill. App. 3d 306, 313 (1998).

Section 2 of the Interest Act provides, in pertinent part, "[c]reditorsshall be allowed to receive at the rate of five (5) per centum per annum for allmoneys after they become due on any *** instrument of writing." 815 ILCS205/2 (West 1998). An insurance policy is an instrument of writing covered bythis statute. Couch v. State Farm Insurance Co., 279 Ill. App. 3d 1050,1054 (1996). In order to recover prejudgment interest, the sum due must beliquidated or subject to an easy determination by calculation or computation. MarvelEngineering Co. v. Commercial Union Insurance Co., 118 Ill. App. 3d 844, 854(1983).

The central issue in this case was the calculation of Lyon's actual losssustained under the business interruption endorsement. Lyon claimed it was due$5,009,105 in addition to the amounts already paid by Protection Mutual pursuantto the property damage and business interruption endorsements to the policy.Protection Mutual claimed that it owed Lyon little or nothing under the businessinterruption endorsement because Lyon had not lost net profit and fixed chargesduring the period of business interruption because it was compensated for itsdamaged inventory. The jury awarded Lyon substantially less than its claimedbusiness interruption loss. See Marvel Engineering Co., 118 Ill. App. 3dat 854. The large difference between what Lyon claimed in business interruptionloss, what Protection Mutual calculated that loss to be, and what the juryultimately awarded is a strong indication that the sum due pursuant to thebusiness interruption endorsement was not easily determined. See Couch,279 Ill. App. 3d at 1055.

Accordingly, we conclude that the trial court did not abuse its discretion indenying Lyon's claim for prejudgment interest, and we affirm the trial court'sdecision.

III. CONCLUSION

For the foregoing reasons, the judgment of the circuit court of Kane Countyis affirmed.

Affirmed.

GROMETER and CALLUM, JJ., concur.