var allSlides;
var currSlide = -1;

function getAllSlides () {
	var allChildren = document.getElementById("slides").childNodes;
	var slideElems = new Array();
	for (var i = 0; i < allChildren.length; i++) {
		if (allChildren[i].nodeType == 1) {
			slideElems[slideElems.length] = allChildren[i];
		}
	}
	allSlides = slideElems;
}

function setHeights() {
	for (var i = 0; i < allSlides.length; i++) {
		allSlides[i].style.height = getInsideWindowHeight() - 200 + "px";
	}
}

function next() {
	showTitle();
	showNext();
	showPrev();
	if (currSlide < 0) {
		allSlides[++currSlide].style.display = "block";
		hideTitle();
		hidePrev();
	}
	else
		if (currSlide < allSlides.length - 1) {
			allSlides[currSlide].style.display = "none";
			allSlides[++currSlide].style.display = "block";
		}
		else
			if (currSlide == allSlides.length - 1) {
				allSlides[currSlide++].style.display = "none";
			}
	if (currSlide == allSlides.length - 1) {
		hideTitle();
		hideNext();
	}
}

function prev()
{
	showTitle();
	showPrev();
	showNext();
	if (currSlide > allSlides.length - 1) {
		allSlides[--currSlide].style.display = "block";
	}
	else
		if (currSlide > 0) {
			allSlides[currSlide].style.display = "none";
			allSlides[--currSlide].style.display = "block";
		}
		else
			if (currSlide == 0) {
				allSlides[currSlide--].style.display = "none";
			}
	if (currSlide == 0) {
		hideTitle();
		hidePrev();
	}
}

function showCard(cardNum) {
	allSlides[currSlide].style.display = "none";
	allSlides[cardNum].style.display = "block";
	currSlide = cardNum;
	if (currSlide == allSlides.length - 1) {
		hideTitle();
		hideNext();
	}
	if (currSlide == 0) {
		hideTitle();
		hidePrev();
	}
}

function hideTitle() {
	/* document.getElementById("pack").style.display = "none"; */
}

function showTitle() {
	/* document.getElementById("pack").style.display = "block"; */
}

function hidePrev() {
	document.getElementById("prevbtn").style.visibility = "hidden";
}

function showPrev() {
	document.getElementById("prevbtn").style.visibility = "visible";
}

function hideNext() {
	document.getElementById("nextbtn").style.visibility = "hidden";
}

function showNext() {
	document.getElementById("nextbtn").style.visibility = "visible";
}

function initSlides()
{
	getAllSlides();
}

function changeSlide(evt) {
	evt = (evt) ? evt : ((window.event) ? event : null);
	if (evt.shiftkey) {
		prev();
	}
	else {
		next();
	}
}