title: IE triggers scroll event more than once
body: <p>This is an event handler:</p>
  
  <pre><code>$(window).on("scroll", function(e){
             e.stopPropagation();    
             e.preventDefault();
             if ((window.innerHeight + document.body.scrollTop) &gt;= document.body.scrollHeight)
                if (window.location.hash=='#/')
                  window.location.hash='#/1'; 
                else
                  window.location.hash='#/';      
         });
  </code></pre>
  
  <p>I have the following problem: Everything is okay in Mozilla and Chrome, however IE changes <code>window.location.hash</code> <strong>more than once</strong> when scrolling is reaching the page bottom and that creates problems.<em>How may I prevent this change to be happened more than once when we scroll down to the bottom?</em></p>