var gIncrement = 15;
var gTimerId = null;
ThreeOhScroll.prototype.scrollDn = function() {
	gTimerId = window.setInterval(this.gRef + ".increment(false)", 25);
}
ThreeOhScroll.prototype.scrollUp = function() {
	gTimerId = window.setInterval(this.gRef + ".increment(true)", 25);
}
ThreeOhScroll.prototype.stopScroll = function() {
	window.clearInterval(gTimerId);
}
ThreeOhScroll.prototype.increment = function(bUp) {
	var iNext = -parseInt(this.content.style.top) + (bUp ? -gIncrement : gIncrement);
	if (iNext <= this.scrollH && iNext >= 0) {
		this.jumpTo(iNext);
	} else if (iNext > this.scrollH) {
		window.clearInterval(gTimerId);
		this.jumpTo(this.scrollH);
	} else {
		window.clearInterval(gTimerId);
		this.jumpTo(0);
	}
}