Mike, one more thing to ask is that the "Property "Exit" is not found" is found due to inactive of current form. But the case is when user Switch to other application (ALT-Tab) and switch back to my application, in rarely case that sometime will out focus of the form and cannot be focus again. That is the strange.
So, I can only solve not prompt "Property "Exit" is not found" by putting the exit code in KeyPress Event, but the application look like hang (cannot be focus by mouse or keyboard, but i sure that it's working, not hang) because the application cannot capture the Exit event due to inactive of form.
So, the main problem is application sudden inactive, therefore, all function use on key label _screen.activeform.xxxx will prompt error and all function use keypress event will no response, any idea?
sohrab100