title: FileUpload Doesn't Work When Nested In UpdatePanel? C#
body: <pre><code> &lt;asp:UpdatePanel ID="UpdatePanel1" runat="server"&gt;
                  &lt;ContentTemplate&gt;
                          &lt;asp:FileUpload onchange="clickTheButton();" ID="FileUpload1" runat="server" /&gt;
                  &lt;/ContentTemplate&gt;
                  &lt;Triggers&gt;
                      &lt;asp:AsyncPostBackTrigger ControlID="Button1" /&gt;
                  &lt;/Triggers&gt;
  &lt;/asp:UpdatePanel&gt;
  </code></pre>
  
  <p>Button 1 is outside the update panel and the javascript that gets run when a user adds a file in the upload box is this:</p>
  
  <pre><code>function clickTheButton() {
              document.getElementById('&lt;%= Button1.ClientID %&gt;').click();
          }
  </code></pre>
  
  <p><strong>The problem is simple.  FileUpload1.HasFile == false.  I don't know why this is, but when I put it in the update panel it ceases to work.</strong></p>
  
  <p>I have seen some other threads on this.  But none of them answer why this is happening, they just point to things you can download.</p>
  
  <p><strong>EDIT: Really my main reason for wanting to do this is so that I can get a ..Uploading File.. Tag to pop up while the client is uploading to the server and once it has completed, display it in a datalist.  I just cant get the UpdateProgress to work.</strong></p>