buttons r not active..

Dear friends,

I am working in <b>mb5t</b> t-code program.I copied the standard program into one zprogram. now i executed the zprogram, its working fine, but <b>back, cancel, exit </b>buttons are <b>disable mode</b>, so i couldn't come back. What i have to make changes in the program. Please suggest me.

Iam Expecting ur Valuable Replay.

Thanks in Advance

Thanuskodi T.