title: Event.ClientX is not working in firefox and chrome
body: <p>I have coding which is working in IE but not in firefox and chrome...</p>
  
  <pre><code> function handleWindowClose() {
              if ((window.event.clientX &lt; 0) || (window.event.clientY &lt; 0))
               {
                   event.returnValue = "Are You sure to leave this page";
               }
           }
           window.onbeforeunload = handleWindowClose;
  </code></pre>
  
  <p>Can anyone help me...</p>