>I have the following problem
>
>I created a form with a text box and a command button to leave the screen.
>
>In the valid clause of my text box, i put the following code
>
>if empty(myfield)
> messagebox("This field is mandatiory......")
> return 0
>else
> return 1
>endif
>
>The problem is i want to quit the form when i click on my button even if myfield is empty, but in my example i can not leave the screen.

You're doing two conflicting things. How can the field be mandatory if you allow them to exit? You will confuse the users with that message and action.