735 ILCS 5/11-110
In all cases where a temporary restraining order or a preliminary injunction is dissolved by the circuit court or by the reviewing court, the circuit court, after the dissolution of the temporary restraining order or preliminary injunction, and before finally disposing of the action shall, upon the party claiming damages by reason of such temporary restraining order or preliminary injunction, filing a petition under oath setting forth the nature and amount of damages suffered, determine and enter judgment in favor of the party who was injured by such temporary restraining order or preliminary injunction for the damages which the party suffered as a result thereof, which judgment may be enforced as other judgments for the payment of money. However, a failure so to assess damages as hereinabove set out shall not operate as a bar to an action upon the injunction bond.
735 ILCS 5/11-110