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.

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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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