JUSTICE LYTTON delivered the opinion of the Court:

Defendant's cousin, John Shannon, was being held on doublehomicide charges at the Kankakee County Jail. Shannon had accessto a cellular phone hidden near his cell and called defendant onDecember 21, 1999. Shannon instructed defendant to go to a certainaddress, pick up a package, and deliver it to Melody Burdunice, acorrectional officer employed at the Kankakee County Jail. Defendant picked up the package and drove to Burdunice's home. Itappears that defendant had known Burdunice for two years and wasaware that she was a Kankakee County Department of Correctionsofficer.

When defendant arrived, Burdunice asked him to accompany herto her room, where she received a call from Shannon. Burdunicetold Shannon that the package, a facial tissue box, was too big tosneak in to the prison. Shannon spoke with defendant and told himto return to his home.

Defendant returned home with the package, and shortlythereafter, Shannon called. Shannon instructed defendant toremove the object from the package and place it in a smaller box. Defendant opened the tissue box, removed some tissues, anddiscovered a gun wrapped among the tissues. Defendant placed thegun inside an empty video cassette tape box and wrapped it in cleartape to keep the box closed.

Later, Burdunice arrived at defendant's home on her way towork at the jail. Defendant gave the box to Burdunice and sheleft. Minutes later, Shannon called and defendant assured him thatBurdunice had picked up the package.

Early the next morning, an inmate at the jail used the gun toshoot a correctional officer and escape. That day, defendant wasarrested at his home. Four days later, the escaped inmate wascaptured. Defendant was tried and convicted of causing another tobring contraband into a prison and aiding escape.

I.

Defendant first claims that the statute prohibiting a personfrom causing another to bring contraband into a prison isunconstitutional. Specifically, defendant argues that no person ofordinary intelligence can understand the meaning of the phrase"cause another," rendering the statute unconstitutionally vague. Since we are evaluating the construction of a statute, our reviewis de novo. People ex rel. Birkett v. City of Chicago, 202 Ill. 2d26, 46 (2002).

For defendant to prevail, he must show that the statute didnot provide clear notice that his conduct was prohibited. Peoplev. Jihan, 127 Ill. 2d 379, 385 (1989). When a statute is examinedin light of the facts of the case and the statute clearly appliesto the party's conduct, then a constitutional challenge based onvagueness must fail. People v. Ryan, 117 Ill. 2d 28, 34 (1987).

The statute in question prohibits a person from bringingcontraband into a prison or causing another to bring contrabandinto a prison. 720 ILCS 5/31A-1.1 (West 2002). It does not define"cause," and in the absence of a statutory definition, terms mustbe given their ordinary meaning. In re Judgment & Sale ofDelinquent Property for Tax Year 1989, 167 Ill. 2d 161, 168 (1995).Cause ordinarily means "to bring about" or "to bring intoexistence." Black's Law Dictionary 213 (7th ed. 1999); see Peopleex rel. Ryan v. McFalls, 313 Ill. App. 3d 223 (2000).

In a decision concerning a drug-trafficking statute, theFourth District held that the phrase "causes to be brought into thestate" was not unconstitutionally vague:

[t]he word "cause" is a common word, easily understood. The statute indicates to any reasonable person thatanyone who knowingly participates in a drug transactionas a result of which controlled substances are broughtinto this State for purposes of manufacture or deliverywill be guilty of a criminal offense *** The defendant'srole as a conduit was an essential link in the chain ofevents which culminated in the delivery of one ounce ofcocaine *** in Springfield, Illinois. People v. Govin, 213 Ill. App. 3d 928, 935 (1991).

The same reasoning applies in this case. The statute indicatesthat any person that knowingly participates in a transaction whichresults in contraband being brought into a prison will be guilty ofa criminal offense. Defendant, by acquiring the gun, repackagingit, and giving it to Burdunice, played an essential role in thedelivery of the gun to the prison. Since the statute prohibitsdefendant's actions, his vagueness claim must fail.

II.

Defendant next argues that he was denied his right to a fairtrial because the court gave improper "double accountability" juryinstructions that are not recognized by Illinois law. The trialcourt instructed the jury to find defendant guilty on the firstcount if the state proved that "the defendant, or one for whoseconduct he is legally responsible, knowingly caused another tobring an item of contraband, to wit: a firearm, into a penalinstitution." The instructions for the escape charge includedsimilar language. Defendant argues that the phrase "or one forwhose conduct he is legally responsible" was confusing andmisleading.

When reviewing a claim based on improper jury instructions, we must first determine whether any error occurred. People v.Dennis, 181 Ill. 2d 87, 95-96 (1998). If we find an error in thejury instruction, we must determine whether, in spite of thaterror, the evidence of defendant's guilt was so clear andconvincing as to render the error harmless beyond a reasonabledoubt. Dennis, 181 Ill. 2d at 96.

A. Contraband Charge

The state argued at trial that defendant was guilty of thecontraband charge as a principal. The inclusion of instructionscharging him as accountable, therefore, might have been confusingto the jury. Since the trial court may have erred by including theaccountability instruction, we must consider whether the error washarmless.

The evidence established that defendant caused the gun to bebrought into the prison. The state made no claim that someone forwhom defendant was legally responsible committed the offense. Neither party argued the merits of the accountability instructionto the jury. We believe that the result would have been the samewithout the accountability instruction. The defendant's guilt asa principal in the offense was clear and convincing; thus theinclusion of the improper accountability instruction was harmlesserror beyond a reasonable doubt.

B. Aiding Escape Charge

We next consider whether the accountability instruction wasproperly given with regard to the aiding escape charge. The courtissued an Illinois Pattern Instruction which defined accountabilityas follows:

[a] person is legally responsible for the conduct ofanother person when, either before or during thecommission of the offense, and with the intent to promoteor facilitate the commission of the offense, he knowinglysolicits, aids, abets, agrees to aid, or attempts to aidthe other person in the planning or commission of theoffense. Illinois Pattern Jury Instructions, Criminal,No. 5.03 (4th ed. 2000).

I.P.I. 5.03 is nearly identical to Illinois' accountabilitystatute. See 720 ILCS 5/5-2(c) (West 2002). Defendant speculatesthat the inclusion of that instruction could have allowed the juryto convict him "even if it believe [sic] the evidence showed thedefendant aided some unknown person, who then aided [theconvict's], a person the defendant never met, escape from jail." Defendant argues that such a theoretical possibility is aconstitutionally unfair deprivation of due process.

We need not theorize about defendant's guilt. At Shannon'srequest and in concert with Burdunice, defendant concealed a gun ina package and provided it to Burdunice for transfer to the prison.These acts resulted in an inmate using that gun to escape from thejail. Defendant aided Shannon's attempted escape, and was,according to Illinois' accountability statute, legally responsiblefor Shannon and Burdunice's actions.

The jury instructions gave the jury the opportunity toconsider defendant's culpability in that escape. It does notmatter, as defendant contends, that he did not personally know theescaped convict. Defendant was accountable for Shannon andBurdunice's actions; since their actions aided the convict'sescape, defendant can also be found guilty of aiding the escape. Here, the accountability instruction was properly given.

III.

Defendant claims that the state failed to prove beyond areasonable doubt that he acted knowingly for each offense. Underthe applicable standard of review, we must consider whether anyreasonable fact finder could have found the essential elements ofthe crime beyond a reasonable doubt when viewing the evidence inthe light most favorable to the prosecution. People v. Collins,106 Ill. 2d 237, 261 (1985).

The criminal code states that one acts with knowledge when itis substantially probable that his conduct violates the statute, orwhen he is consciously aware that the illegal result of his conductis practically certain to be caused by his conduct. 720 ILCS 5/4-5(West 2002). Knowledge may be inferred from the facts and thecircumstances of the case. People v. Holt, 271 Ill. App. 3d 1016(1995).

The evidence establishes that: (1) defendant was incommunication with Shannon, (2) he knew Burdunice worked at theprison, (3) he knew that Burdunice was also in contact withShannon, (4) he packaged and concealed a gun that he ultimatelygave to Burdunice on her way to the prison, and (5) he knew Shannonwas going to try to use the gun to help him and a fellow inmateescape. These facts are sufficient to establish that defendantacted knowingly for both offenses. Under the Collins standard, arational trier of fact could have found the essential elementsbeyond a reasonable doubt.

IV.

Defendant argues that his conviction should be reversed because apublic act that amended the statute under which he was convicted violated the single subject rule of the Illinois Constitution.

The single subject rule states that legislative bills, with few exceptions, must be confined to one subject. Ill. Const. 1970,art. IV,