var timer;
  var speed = 5;
  
  function init()
  {
    contentTop  = 0;//getTop(document.getElementById("content_layer"));
    contentLeft = getLeft(document.getElementById("content_layer"));
    document.getElementById("content").style.top = contentTop + "px";
    document.getElementById("content").style.Left = contentLeft + "px";
  }
  
  
  function getTop(MyObject)
  {
    if (MyObject.offsetParent)
        return (MyObject.offsetTop + getTop(MyObject.offsetParent));
    else
        return (MyObject.offsetTop);
  }
  
  function getLeft(MyObject)
  {
    if (MyObject.offsetParent)
        return (MyObject.offsetLeft + getLeft(MyObject.offsetParent));
    else
        return (MyObject.offsetLeft);
  }
  
  function scrollup()
  {
    var contentHeight = document.getElementById("content").offsetHeight;
	//var contentTop = getTop(document.getElementById("content"));
    var layerHeight = document.getElementById("content_layer").offsetHeight;
    var layerTop = getTop(document.getElementById("content_layer"));
    
 
    if( contentTop > document.getElementById("content_layer").offsetHeight - contentHeight)
    {
      contentTop -= speed;
      document.getElementById("content").style.top = contentTop;
      timer=setTimeout("scrollup()",25);
    }
  }
  
  function scrolldown()
  {
    var contentHeight = document.getElementById("content").offsetHeight;
	//var contentTop = getTop(document.getElementById("content"));
    
    if( contentTop < 0 )
    {
      contentTop += speed;
      document.getElementById("content").style.top = contentTop;
      timer=setTimeout("scrolldown()",25);
    }
  
  }
  
  function stopScroll()
  { 
    clearTimeout(timer);
  }