var scrollTick = 5;
var scrollTimerSpeed = 10;
var scrollTimer = setTimeout("");

function scrollUp() {
	if ( document.getElementById ) {
		clearScroll();
		scrollTimer = setTimeout("doScrollUp()", scrollTimerSpeed);
	}
}

function scrollDown() {
	if ( document.getElementById ) {
		clearScroll();
		scrollTimer = setTimeout("doScrollDown()", scrollTimerSpeed);
	}
}

function doScrollUp() {
	var scrollClip=document.getElementById("scrollClip");
	if ( parseInt(scrollClip.style.top) < 0 ) {
		scrollClip.style.top = Math.min (parseInt(scrollClip.style.top) + scrollTick, 0);
	}	
	var value = Math.min(parseInt(scrollClip.style.top)/(parseInt(scrollClip.offsetHeight) - scrollHeight)*-1,1);
	slider.setValue(value);
	scrollTimer = setTimeout("doScrollUp()", scrollTimerSpeed);
}

function scrollTo(value) {
	$('scrollClip').style.top = (value*-1)*(parseInt($('scrollClip').offsetHeight) - scrollHeight);
}

function doScrollDown() {
	var scrollClip=$("scrollClip");
	if ( parseInt(scrollClip.offsetHeight)+parseInt(scrollClip.style.top) > scrollHeight ) {
		scrollClip.style.top = parseInt(scrollClip.style.top) - scrollTick;
	}
	
	var value = Math.min(parseInt(scrollClip.style.top)/(parseInt(scrollClip.offsetHeight) - scrollHeight)*-1,1);
	slider.setValue(value);
	scrollTimer = setTimeout("doScrollDown()", scrollTimerSpeed);
}

function clearScroll() {
	clearTimeout(scrollTimer);
}

window.onload=function() {
	if ( document.getElementById ) {
		var scrollClip=$("scrollClip");
		if ( scrollClip ) {
		if ( parseInt(scrollClip.offsetHeight) > scrollHeight ) {
/*			alert("they are going on!");*/
//			document.getElementById("arrows").style.visible = true;
			$("scroller").style.visibility = "visible";
		}
		}
	}
}