How to stop postback when calling usercontrol

Question

I have a ModalPopupExtender control and a panel which contains a iframe. The ModalPopupExtender's TargetControlID property is set to a html button control named btnFind.

When I click to find button, the panel with its iframe control shows as a modal popup.

This is work fine,but then I decided to take these control to an usercontrol and use this simplier and many times. I made it, and it works, but when I call usercontrol to open modal popup, my Main page is postbacking. I couldn't stop it. My user control's syntax is below. Can anyone give me some advices to stop the postback?

<PBG:Modal ID="mdlFind" runat="server" Height="460" Width="840" TargetControlId="btnFind" />

Answer 1

Try removing runat="server"