title: Image URL not changing in Update panel
body: <p>Ok this is probably really simple but I have been staring at it for too long now. <br/>
  I have an AJAX AsyncFileUpload control that when a file is selected I want the Image next to it to change. I tried it in Javascript and it did nothing, i have since tried it server-side and still nothing. here is the client side. <br/></p>
  
  <pre><code>  &lt;asp:UpdatePanel runat="server" ID="upnlConfidential"&gt;
      &lt;ContentTemplate&gt;
    &lt;td&gt;
    &lt;asp:AsyncFileUpload ID="_flupCV" runat="server" OnUploadedComplete="AdminFileUpload" /&gt;
     &lt;/td&gt;
     &lt;td&gt;
     &lt;asp:Image ID="imgCV" runat="server" Height="25px" Width="25px" ImageUrl="~/Images/Exclamation.png"/&gt;
  &lt;/td&gt;
  &lt;/ContentTemplate&gt;
  &lt;/asp:UpdatePanel&gt;
  </code></pre>
  
  <p>and here is the server side</p>
  
  <pre><code>        protected void AdminFileUpload(object sender, AjaxControlToolkit.AsyncFileUploadEventArgs e)
      {
          AjaxControlToolkit.AsyncFileUpload upload = (AjaxControlToolkit.AsyncFileUpload)sender;
          if (upload.PostedFile != null)
          {
              switch (upload.ID)
              {
                  case "_flupCV":
                      ImageCheckMark(imgCV);
                      break;
                //etc...
              }
          }
      }
      private void ImageCheckMark(Image image)
      {
          image.Visible = true;
          image.ImageUrl = "~/Images/CheckMark.png";
      }
  </code></pre>
  
  <p>When the server side is called it sets the URL just fine but then nothing happens to the image, when I call the code again the URL is still the previous Exclamation image. its almost like its forgotten. <br/></p>
  
  <p>Can anybody help me on this please. Thanks in advance to all who contribute!</p>