JAVASCRIPT: Ajax response

common.js

/*function clientSideInclude(id, url) {
  var req = false;
  // For Safari, Firefox, and other non-MS browsers
  if (window.XMLHttpRequest) {
    try {
      req = new XMLHttpRequest();
    } catch (e) {
      req = false;
    }
  } else if (window.ActiveXObject) {
    // For Internet Explorer on Windows
    try {
      req = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
      try {
        req = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (e) {
        req = false;
      }
    }
  }
 var element = document.getElementById(id);
 if (!element) {
  alert("Bad id " + id +
   "passed to clientSideInclude." +
   "You need a div or span element " +
   "with this id in your page.");
  return;
 }
  if (req) {
    // Synchronous request, wait till we have it all
    req.open('GET', url, false);
    req.send(null);
    element.innerHTML = req.responseText;
  } else {
    element.innerHTML =
   "Sorry, your browser does not support " +
      "XMLHTTPRequest objects. This page requires " +
      "Internet Explorer 5 or better for Windows, " +
      "or Firefox for any system, or Safari. Other " +
      "compatible browsers may also exist.";
  }
}*/
(function(){
  $.ajax({
    type: "GET",
    url: "nav-file.html" 
  }).done(function( msg ) {
    //alert( "Data Saved: " + msg );
    $("#nav-file").html(msg);

  }); 
})