title: how to set focus on textbox after post back in asp.net
body: <p>i have a textbox in update panel. when a user type something i fetch related data from database and fill that in another textbox. My problem is that after autopostback focus on any of the textboxs is lost. How can i manage this using javascript or code because i used both like in code i used </p>
  
  <pre><code> System.Web.UI.ScriptManager.GetCurrent(this).SetFocus(this.txtReference);
  </code></pre>
  
  <p>and javascript i find one more that is </p>
  
  <pre><code>    &lt;script type="text/javascript"&gt;
      var postbackElement;
      Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginRequest);
      Sys.WebForms.PageRequestManager.getInstance().add_pageLoaded(pageLoaded);
  
  
      function beginRequest(sender, args) {
          postbackElement = args.get_postBackElement();
      }
  
  
      function pageLoaded(sender, args) {
          var updatedPanels = args.get_panelsUpdated();
          if (typeof (postbackElement) === "undefined") {
              alert('if Loop');
              return;
          }
          else if (postbackElement.id.toLowerCase().indexOf('button1') &gt; -1) {
          alert('else');
              for (i = 0; i &lt; updatedPanels.length; i++) {
  
                  document.getElementById('&lt;%= txtAcctNo.ClientID %&gt;').focus();
              }
          }
  
  
      }
  &lt;/script&gt;
  </code></pre>
  
  <p>but not working because 'button1 undefined'.
  What i place there because all event performed on OnTextChanged="" in aspx page.</p>
  
  <p>So please help me through code or javascript how can i do this .</p>