title: Why I double-click on button in some asp.net web applications?
body: <p>I am writing asp.net application. I have a little problem in button click.
  In some page, the event cannot drive to server side immediately. So I need to click twice. But not on all pages. I use the same control on another page. Why does this happen on these page? I simply write the code. I search in internet and google. I cannot find the exact answer.</p>
  
  <pre><code> &lt;uc2:SaveUpdateCancelButtons ID="butCmd" runat="server" 
        OnButtonClick="butCmd_Click" TabIndex="5" /&gt;
  
  protected void butCmd_Click(object sender, EventArgs e, ButtonCommands command)
  {
      //...
  }
  </code></pre>