function backToTop() {
	el = document.getElementById("pagewrap");
	el.scrollTop = Math.floor(el.scrollTop/2);	
	var y = el.scrollTop || 0;
	if(y > 0)
    	window.setTimeout("backToTop()", 25);
}

function addBackToTop() {
	var links = getElementsByClassName(document.getElementById("content"),"A","backtotop");	
	for(i=0;i<links.length;i++)	
		addEvent(links[i],"click",backToTop);
}

function addEvent( obj, type, fn )
{
  if (obj.addEventListener)
    obj.addEventListener( type, fn, false );
  else if (obj.attachEvent)
  {
    obj["e"+type+fn] = fn;
    obj[type+fn] = function() { obj["e"+type+fn]( window.event ); }
    obj.attachEvent( "on"+type, obj[type+fn] );
  }
}

function removeEvent( obj, type, fn )
{
  if (obj.removeEventListener)
    obj.removeEventListener( type, fn, false );
  else if (obj.detachEvent)
  {
    obj.detachEvent( "on"+type, obj[type+fn] );
    obj[type+fn] = null;
    obj["e"+type+fn] = null;
  }
}

function getElementsByClassName(oElm, strTagName, strClassName){
    var arrElements = (strTagName == "*" && document.all)? document.all : 
    oElm.getElementsByTagName(strTagName);
    var arrReturnElements = new Array();
    strClassName = strClassName.replace(/\-/g, "\\-");
    var oRegExp = new RegExp("(^|\\s)" + strClassName + "(\\s|$)");
    var oElement;
    for(var i=0; i<arrElements.length; i++){
        oElement = arrElements[i];      
        if(oRegExp.test(oElement.className)){
            arrReturnElements.push(oElement);
        }   
    }
    return (arrReturnElements)
}


addEvent(window, "load", addBackToTop);