Preventing Bang out of Perform

Hi, I'm a first time caller. I wrote a Unix shell script which serves as a menu system for users to run Informix reports, forms, etc. The script is invoked at login via .profile, and the TRAP command prevents users from breaking out of the menu with the delete key. I don't want anyone to remove or overwrite any of my files. However, they still could bang out an Informix form with a ! and be on their merry way. Is there something I can do to prevent the bang in Perform? hoinj@cc.tacom.army.mil