Writing a bad check in Illinois is covered under the Criminal Code as 'deception' (720 ILCS 5, Art. 17).
"Sentence.
A person convicted of deceptive practice under paragraphs (a) through (e) of this subsection (B), except as otherwise provided by this Section, is guilty of a Class A misdemeanor.
A person convicted of a deceptive practice in violation of paragraph (d) a second or subsequent time shall be guilty of a Class 4 felony.
A person convicted of deceptive practices in violation of paragraph (d), when the value of the property so obtained, in a single transaction, or in separate transactions within a 90 day period, exceeds $150, shall be guilty of a Class 4 felony. In the case of a prosecution for separate transactions totaling more than $150 within a 90 day period, such separate transactions shall be alleged in a single charge and provided in a single prosecution."
The FULL statute with descriptions can be found at:
http://www.legis.state.il.us/legislation/ilcs/ilcs2.asp?ChapterID=53