Ok i have setup validation using RequiredFieldValidator etc, works great. here's the problem... if you press submit and there are errors, the error messages display, then if the user selects something from my dropdown list which has AutoPostBack on then the errors disappear til u press submit again. how can i fix this? fyi i have autopostback on because i need to check weather a certain item is selected in that dropdownlist to display another textbox.

Using VS 2003, C# Webform