function RollUp() {
	if (inProcess)
		resetRollUp();
	nextPic = (nextPic == (numImgs - 1)) ? 0 : nextPic += 1;
	var oldSlide = 'image' + ((oneIsOn) ? 1 : 2);
	var newSlide = 'image' + ((!oneIsOn) ? 1 : 2);
	oneIsOn = !oneIsOn;
	topDimension = tp = 0;
	rightDimension = rt = getElementWidth(newSlide);
	leftDimension = lt = 0;
	bottomDimension = bt = getElementHeight(newSlide);
	setClip(newSlide, bt, rt, bt, lt); // Position new image!
	slideLt = getEl(newSlide).style.left;
	slideTp = getEl(newSlide).style.top;
	oldS = oldSlide;
	newS = newSlide;
	getEl(oldSlide).style.zIndex = 1;
	getEl(newSlide).style.zIndex = 5;
	transMoveTo(getEl(newSlide), 0, bottomDimension);
	getEl(oldSlide).style.visibility = 'visible';
	getEl(newSlide).style.visibility = 'visible';
	inProcess = true;
	timerID = setInterval("rollUp('" + oldSlide + "','" + newSlide + "')", delay);
}


function resetRollUp() {
	getEl(oldS).style.visibility = 'hidden';
	clearInterval(timerID);
	setClip(oldS, topDimension, rightDimension, bottomDimension, leftDimension);
	getEl(oldS).style.left = slideLt;
	getEl(oldS).style.top = slideTp;
	setClip(newS, topDimension, rightDimension, bottomDimension, leftDimension);
	getEl(newS).style.left = slideLt;
	getEl(newS).style.top = slideTp;
	getEl(oldS).src = imgAry[nextPic].src;
	inProcess = false;
}

function rollUp(oldSlide, newSlide) {
	tp += (step * 2);
	if (tp >= bottomDimension)
		resetRollUp();
	else {
		setClip(oldSlide, tp, rt, bt, lt);
		transMoveTo(getEl(oldSlide), 0, (step * -2));
		transMoveTo(getEl(newSlide), 0, (step * -2));
		setClip(newSlide, topDimension, rt, tp, lt);
	}
}