var funcs = function(){
	PageTop.Load();
}

AddEventListener(window,'load',funcs);

function PageTop(){}

PageTop.Load = function(){
	var pTags = document.getElementsByTagName("p");
	var nowHeight;
	var timerID;
	for(i=0;i<pTags.length;i++){
		if(pTags[i].className.indexOf("pagetop") >= 0){
			var clickObject = pTags[i].firstChild;
			AddEventListener(clickObject,'click',MoveSet);
		}
	}
	function MoveSet(e){
		timerID = setTimeout(Move,0);
		
		StopPropagation();
		PreventDefault(e);
	}
	function Move(){
		var nowScrollY;
		if(GetBrowser() == "Safari"){
			nowScrollY = document.body.scrollTop;
		}else{
			nowScrollY = document.documentElement.scrollTop;
		}
		
		if(nowScrollY > 0){
			var step = nowScrollY * 0.07;
			if(step < 1){
				step = 0.5;
			}
			if(GetBrowser() == "Safari"){
				document.body.scrollTop = nowScrollY - step;
			}else{
				document.documentElement.scrollTop = nowScrollY - step;
			}
			setTimeout(Move,0);
		}else{
			if(GetBrowser() == "Safari"){
				document.body.scrollTop = 0;
			}else{
				document.documentElement.scrollTop = 0;
			}
			clearTimeout(timerID);
		}
	}
}