Hi!
          I am writing java script. i need to validate a text box in a form before submiting.i.e. if any wrong or no data in textbox it has to give an alert.I did that but after alert, it is moving to action method.It should not move to next form(i.e, focus on the same form).
thank u.

Assuming your validation function is called validateData you need to return false from it if the validation fails, true otherwise.
In your form's onsubmit attribute you need:--

Joe (Microsoft MVP - XML)