Disabling an (posted by Aaron)
I consistently see people looking for easy ways to disable asp:buttons after they're clicked. The most common problem is that a user will click a button 20+ times not knowing that their action has been sent to the server. As you know, this can create a big problem really click. There are ways to avoid this on the server obviously, but easiest and most friendly solution would be just to disable the button after it's clicked.
Well, if you've ever tried, you realize that what seems like an easy task - isn't. If you add any code to the button to force it to a disabled state after being clicked the postback event never fires. Argh.
Well, here's an easy way to accomplish the exact same thing but instead of using an asp:button you simply using an input button with runat="server". Works like a charm.
<input type="button" id="btnNext" runat="server" value="Next" onserverclick="btnNext_Click" onclick="this.disabled=true;">