Illinois Statutes Chapter 720. Criminal Offenses § 5/15-9. Value

(a) The “market value” of such instrument if such instrument is negotiable and has a market value; and

(b) The “actual value” of such instrument if such instrument is not negotiable or is otherwise without a market value. For the purpose of establishing such “actual value”, the interest of any owner or owners entitled to part or all of the property represented by such instrument, by reason of such instrument, may be shown, even if another “owner” may be named in the complaint, information or indictment.