title: How can I get rid of the "Are you sure you want to leave this page" message?
body: <p>How can I get rid of the "Are you sure you want to leave this page" message?</p>
  
  <p>I try to use <code>window.onBeforeunload=null</code> and it works for Chrome, but it did not work for Firefox, Internet Explorer and Opera.</p>
  
  <p>Thanks in advance.</p>