delay=40;downTimer=0; upTimer=0;
function goDown(pixels) {
	obj.scrollTop=obj.scrollTop+pixels;
	downTimer=setTimeout('goDown('+pixels+')',delay);
}
function goUp(pixels) {
	obj.scrollTop=obj.scrollTop-pixels;
	upTimer=setTimeout('goUp('+pixels+')',delay);
}
function goStop() {
	if(downTimer) clearTimeout(downTimer);
	if(upTimer) clearTimeout(upTimer);
}
function initScroller() {
	obj=document.getElementById('content');
	if(obj.scrollHeight-obj.clientHeight>0) document.getElementById('divup').style.visibility='visible';
	if(obj.scrollHeight-obj.clientHeight>0) document.getElementById('divdown').style.visibility='visible';
}

window.onload = initScroller;