function scrollDone()
{
	(document.body.scrollLeft > 0) ? document.getElementById("arrow_left").style.display = '' : document.getElementById("arrow_left").style.display = 'none';
	(document.body.scrollWidth-document.body.offsetWidth <= document.body.scrollLeft) ? document.getElementById("arrow_right").style.display = 'none' : document.getElementById("arrow_right").style.display = '';
}

window.onscroll = scrollDone;

var a_scroll_status = 0;
var delta;

function aScroll(direction)
{
	(direction == "right") ? delta = 1 : delta = -1;
	a_scroll_status = 1;
	aScrollAction();
}

function aScrollAction()
{
	if(a_scroll_status)
	{
		document.body.scrollLeft += delta*30;
		setTimeout('aScrollAction()', 20);
	}
}

function scrollStop()
{
	a_scroll_status = 0;
}