var defaultStep = 1;
var step = defaultStep;
var timerDown = "";
var timerUp = "";

function scrollDown(id) {
	window.clearTimeout(timerDown);
	document.getElementById(id).scrollTop += step;
	timerDown = setTimeout("scrollDown('" + id + "')", 10)
}

function scrollUp(id) {
	window.clearTimeout(timerUp);
	document.getElementById(id).scrollTop -= step;
	timerUp = setTimeout("scrollUp('" + id + "')", 10)
}

function stopMe() {
	clearTimeout(timerDown);
	clearTimeout(timerUp);
}