Validation in imagebutton, button not occuring

In my project, validation is not occurring at button_click and imagebutton_click. Why could it be so?

I also gave same validation group to all validators and button and开发者_如何学编程 also CAUSEVALIDATION "true" in button

Please help solve this.

Add validation group to image button too and check. Also check if your image button has image in it. Other wise it will not fire events

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<asp:TextBox ID="txt_password" runat="server" CssClass="text_box_password" TextMode="Password" Width="180px"></asp:TextBox> 
<asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" ControlToValidate="txt_password" ErrorMessage="*" ValidationGroup="aaaa">**</asp:RequiredFieldValidator>

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