How to ask for user confirmation when submitting a form using FAPI What I want is suppose a user enters same data twice in two rows then I want to show her an error/warning and now if she chooses to press submit again then I'd process and accept the form.

How to do it?
use the confirm_form function. See Here and Here for examples


  This function returns a complete form array for confirming an action.
  The form contains a confirm button as well as a cancellation link that
  allows a user to abort the action.