Autopostback=True for a Textbox and RequiredFieldValidator next to it. But when submitting form after Posting back by TextChanged event to the Textbox, RequiredFieldValidator doesn't work!?

Question

Hi In my .aspx form I have a textbox (Textbox1) with Autopostback=True. I also set a RequiredFieldValidator (RequiredFieldValidator1) next to it. But when Posting back by TextChanged event of Textbox1, RequiredFieldValidator1 appears but still I can submit my form with nothing into the Textbox1!

what's wrong?

Answer 1

You have to set the textbox's CausesValidation property to true (it's set to false by default for textboxes).

Answer 2

give both the text box and the submit button the same validation group ...