Patent ID: 8175916

Claim:
An image forming system for printing an image on a printing sheet, comprising: a sheet accommodating section having a plurality of sheet trays each accommodating therein printing sheets with advertisement each carrying an advertisement previously printed thereon; an image forming section configured to print an image on a printing sheet fed from the sheet accommodating section; a term management server having stored therein information on a term of validity of the advertisement carried by a printing sheet with advertisement as advertisement term information connected with a sheet tray accommodating therein the printing sheet with advertisement; and a CPU configured to detect whether or not the advertisement carried by each of the printing sheets with advertisement accommodated in each of the sheet trays is currently valid, based on the advertisement term information stored in the term management server, wherein: the CPU determines during printing whether or not the term of validity of the advertisement carried by each of the printing sheets with advertisement accommodated in a sheet tray being used in printing has expired; and the image forming system suspends printing when it is determined that the term of validity of the advertisement carried by each of the printing sheets with advertisement accommodated in the sheet tray being used in printing has expired, the image forming system further comprises a display section configured to display information that a sheet tray other than the sheet tray being used is present which accommodates therein printing sheets with advertisement each carrying an advertisement which is currently valid, if any.