title: FileUpload control postback problem
body: <p>I'm having a FileUpload control on a aspx page inside a UpdatePanel with a button on click of which I want to set a label with the filename of the selected file.</p>
  
  <p>Here is the code I have:</p>
  
  <p>ASPX PAGE:</p>
  
  <pre><code>&lt;div&gt;
      &lt;asp:ScriptManager ID="ScriptManager1" runat="server"&gt;
      &lt;/asp:ScriptManager&gt;
      &lt;asp:UpdatePanel ID="UpdatePanel1" runat="server"&gt;
          &lt;ContentTemplate&gt;
              &lt;asp:FileUpload runat="server" ID="fuSimple"&gt;&lt;/asp:FileUpload&gt;
              &lt;asp:Button runat="server" Text="Button" ID="btnPostback" 
                  onclick="btnPostback_Click" /&gt;
              &lt;br /&gt;
              &lt;asp:Label ID="lblFileName" runat="server" Text="File Name: "&gt;&lt;/asp:Label&gt;
          &lt;/ContentTemplate&gt;
      &lt;/asp:UpdatePanel&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Code Behind:</p>
  
  <pre><code>protected void btnPostback_Click(object sender, EventArgs e)
      {
          lblFileName.Text = "File Name: " + fuSimple.FileName;  
      }
  </code></pre>
  
  <p>Every time I hit the button, I'm getting an empty string. What am I missing?</p>
  
  <p>Also, when I do this without UpdatePanel it works fine.</p>
  
  <p>Comments/help appreciated.</p>