var t
var scroll_element = "work_grid";
var y = 0;
var clip_bottom = 192




function stopScroll()
{
	clearInterval(t)
}


function scroll(inc)
{
	clearInterval(t)
	var sobj = document.getElementById(scroll_element);
	var h = sobj.offsetHeight
	
	if(h && h <= clip_bottom)
	{
		document.getElementById("up").style.visibility = "hidden"
		document.getElementById("down").style.visibility = "hidden"
	}
	
	
	
	y += inc
	
	
	y = Math.min(h-clip_bottom,y)
	
	y = Math.max(0,y)
	
	sobj.style.top = -y+"px";
	
	
	sobj.style.clip = "rect("+y+"px,"+sobj.offsetWidth+"px,"+(y+clip_bottom)+"px,0px)"
	sobj.style.visibility = "visible"
	

	t = setInterval("scroll("+inc+")",50);
	
	

}