Jquery slide in div keeps moving on scroll
<p>I have aa div that I want to slide in once the user scrolls down a specified amount. It initially works but after than the div keeps moving to the left a little on every scroll action instead of staying in place. Anyone has an idea why is this happening?</p>

<pre><code>  var opening = false;
  var closing = false; 
 $(window).scroll(function(){
     var windowHeight = $(window).height();
     var windowScroll = $(window).scrollTop(); 
     var position1 = $("#Support").offset().top;         
    if ( windowScroll &gt; (position1 - (windowHeight/2)) )  
     {
        if (!opening) {
            opening = true;
            closing = false;
            $("#SupportImage1").stop().animate({
                left: "1200px"                  
              }, 1500, function(){
                  opening = false;
                  });
            }            
     }
     else
     {
        if (!closing) {
            closing = true;
            opening = false;
             $("#SupportImage1").stop().animate({
                left: "100%"                    
              }, 1400, function() {
                  closing = false;
              });                
        }
     }       
 });
</code></pre>
