Recently i faced some strange problem with required field validator, inside a update panel its not working, since some controls are dynamically loaded with required field validattion.
<asp:TextBox id=”txtDummy” runat=”server” Visible=”false”/>
<asp:RequiredFieldValidator ID=”reqDummy1″ runat=”server” ControlToValidate=”txtDummy” Text=”*” ValidationGroup=”DummyValgroup” ErrorMessage=”Please provide text”></asp:RequiredFieldValidator>
This helps to do the validation for dynamically created controls with validation.
I hope this may helpful for