var totalEls = 0;
var scroll = false;
var globalId;
var globalHeight = 20;

function startScroll(id, up,total,itemHeight)
{
	scroll = true;	
	if (up == true)
		scrollUp(id);	
	else
		scrollDown(id);	
	totalEls = total;
	if(itemHeight != undefined)
	{
	//alert(itemHeight)
		globalHeight = itemHeight
	}
}

function endScroll()
{
	scroll = false;	
}

function scrollDown(id)
{
//alert(scroll);
	if (!scroll)
		return;

	if (id == undefined)
	{
		id = globalId;
	}
	else
	{
		globalId = id;
	}

	maxTop = globalHeight * (totalEls - 5);
	marginTop = document.getElementById(id).style.marginTop;
	margTop = marginTop.substring(0, marginTop.indexOf('px'));
	if (margTop == "")
		margTop=0;

	if (margTop > -maxTop)
	{
		margTop -= 2;
		document.getElementById(id).style.marginTop= margTop + 'px';
		setTimeout("scrollDown()", 30);
	}
}

function scrollUp(id)
{
	if (!scroll)
		return;

	if (id == undefined)
	{
		id = globalId;
	}
	else
	{
		globalId = id;
	}

	marginTop = document.getElementById(id).style.marginTop;
	margTop = marginTop.substring(0, marginTop.indexOf('px'));
	if (margTop == "")
		margTop=0;
	margTop = parseInt(margTop);
	
	if (margTop < 0)
	{
		margTop += 2;
		document.getElementById(id).style.marginTop= margTop + 'px';
		setTimeout("scrollUp()", 30);
	}
}