title: Update progress Causing Flash Effect in Partial Updates
body: <p>i Showing a progress Bar as a Modal Pop Up.for this i </p>
  
  <pre><code>&lt;script type="text/javascript" language="javascript"&gt;
          Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginReq);
          Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endReq);
  
          function beginReq(sender, args) {
              // shows the Popup 
              $find(ModalProgress).show();
          }
  
          function endReq(sender, args) {
              //  shows the Popup 
              $find(ModalProgress).hide();
          } 
  
  
      &lt;/script&gt;
  </code></pre>
  
  <p>Update Panel trigger </p>
  
  <pre><code>&lt;Triggers&gt;
        &lt;asp:AsyncPostBackTrigger ControlID="ChVerifed" EventName="CheckedChanged" /&gt;
   &lt;/Triggers&gt;
  </code></pre>
  
  <p>This will execute for every asynchronous request. Can i put a condition for certain update panel make this to invoke .i not found a solution for this anywhere.In my project.there so many update panel and many are nested panel.this cause a flash effect everytime for an asynchrounus Request. i used the update parameter as conditional but this also not Working</p>