var scrollTarget = 0;
var scrollCurrent = scrollTarget;
var scrollInterval = null;
var scrollElement = null;
var scrollContainer = null;
var scrollSpeed;

function initialize(element, container){
	var obj = document.getElementById(element);
	var con = document.getElementById(container);
	if(!obj || !con) return;
	scrollElement = obj;
	scrollContainer = con;
	var containerHeight = scrollContainer.scrollHeight;
	var scrollableHeight = scrollElement.scrollHeight;
	containerHeight > scrollableHeight ? null : getScrollbar().style.visibility = "visible";
}

function scroll(dir){
	scrollSpeed = 20;
	scrollTarget += dir;
	var diff = scrollContainer.offsetHeight-scrollElement.scrollHeight;
	if(scrollTarget < diff)
		scrollTarget = diff;
	if(scrollTarget > 0)
		scrollTarget = 0;
	scrollInterval = setInterval("enterFrame()", 40)
}

function enterFrame(){
	if(Math.abs(scrollElement.offsetTop-scrollTarget) > 1)
		scrollCurrent += (scrollTarget-scrollCurrent)/scrollSpeed;
	else
		clearInterval(scrollInterval);
	scrollSpeed += (4-scrollSpeed)/15;
	scrollElement.style.top = scrollCurrent+"px";
}

function getScrollbar(){
	return document.getElementById("scrollbar");
}