var increment=2;
    var rate=10; //In milliseconds
    var currPos=0;
    var canShiftRight=false;
    var canShiftLeft=false;

    function showMargin(obj)
    {
	obj.style.opacity = .1;
	obj.style.filter = 'alpha(opacity=10)';
      obj.style.backgroundColor = 'red';
    }

    function shiftRight(obj)
    {
     var hoverScroll=obj.parentNode;

     if(canShiftRight)
     {
      showMargin(obj);
      currPos-=increment;
      hoverScroll.style.backgroundPosition=""+ currPos + "px 0px";
      setTimeout("shiftRight(document.getElementById(\"leftMargin\"))", 100);
     }
    }

    function shiftLeft(obj)
    {
     var hoverScroll=obj.parentNode;
     
     if(canShiftLeft)
     { 
      showMargin(obj);
      currPos+=increment;
      hoverScroll.style.backgroundPosition=""+ currPos + "px 0px";
      setTimeout("shiftLeft(document.getElementById(\"rightMargin\"))", 100);
     }
    }

    function hideMargin(obj)
    {
	obj.style.opacity = .5;
	obj.style.filter = 'alpha(opacity=50)';
      obj.style.backgroundColor = 'white';
    }