>Yes I did that sir, but the cursor moves to another column still.
>
>What should I do?

Try to add a messagebox or something, to make sure that the check really returns .F. Another solution is to add the check to the next textbox's GotFocus, something like

If !YourCheckFunc()
   Messagebox("Wrong value",16,'Alert',3000)
   This.parent.columnX.textbox.sefocus()
Endif