I'm not entirely sure what you're asking here. If you mean, "Can you toggle on or off the setting for FileMaker to prompt the user whether to save the record changes" (i.e., the setting in the Layout Options dialog), the answer is no.
However, you can use an OnRecordCommit trigger to accomplish much the same task. This trigger will fire whenever any action is taken by the user that would normally cause a record to commit (e.g., pressing "Enter", switching layouts, changing records, closing the window). Inside that script, you can perform pretty much any action you need.
you understand well.
What I meant to say is in your first answer... But your second answer gave me the solution that I was looking for.
Thanks a lot