form postback and validation

Question

Hi, I am new to .Net and come from Java. I have a form in a page. I tell the form to go to a second page in the Button object with postbackurl. Before, I make some validation using a CustomValidator. The method in the validator just sets the args.IsValid to false. In case of a bad validation, I am redirected to the second page, instead of staying at the same page, though the validation method is called. My code: Validation: public void myValidate(object source, System.Web.UI.WebControls.ServerValidateEventArgs args) { if (...) { args.IsValid = false; } } Button definition: Any hint on what goes wrong? Thank you Samuel