var swapVertStep = 2;
var swapVertDelay = 6;

function SwapVert() {
	if (inProcess) return;
		// resetSwapVert();
	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 = 442;
	leftDimension = lt = 0;
	bottomDimension = bt = 620;
	oldS = oldSlide;
	newS = newSlide;
	getEl(oldSlide).style.zIndex = 5;
	getEl(newSlide).style.zIndex = 1;
	getEl(oldSlide).style.visibility = 'visible';
	getEl(newSlide).style.visibility = 'visible';
	inProcess = true;
	timerID = setInterval("swapVertOut('" + oldSlide + "','" + newSlide + "')", swapVertDelay);
}

function resetSwapVert() {
	if (timerID) clearInterval(timerID);
	getEl(oldS).style.visibility = 'hidden';
	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).top = slideTp;
	getEl(oldS).src = imgAry[nextPic].src;
	inProcess = false;
}

function swapVertOut(oldSlide, newSlide) {
	if ((bt - swapVertStep) <= (bottomDimension / 2))
		swapSwitchVert(oldSlide, newSlide);
	else
		doSwapVert(oldSlide, newSlide, swapVertStep);
}

function swapSwitchVert(oldSlide, newSlide) {
	if (timerID) clearInterval(timerID);
	getEl(oldSlide).style.zIndex = 1;
	getEl(newSlide).style.zIndex = 5;
	timerID = setInterval("swapVertIn('" + oldSlide + "','" + newSlide + "')", swapVertDelay);
}

function swapVertIn(oldSlide, newSlide) {
	if (tp <= topDimension)
		resetSwapVert();
	else
		doSwapVert(oldSlide, newSlide, -swapVertStep);
}

function doSwapVert(oldSlide, newSlide, swapStep) {
	bt -= swapStep * 2;
	tp += swapStep * 2;
	setClip(oldSlide, tp, rt, bottomDimension, lt);
	transMoveTo(getEl(oldSlide), 0, (swapStep * -2));
	transMoveTo(getEl(newSlide), 0, (swapStep * 2));
	setClip(newSlide, topDimension, rt, bt, lt);
}