// JavaScript Document

function switcher (img) {
	photo = document.getElementById('switcherPhoto');
	photo.src=img;
	photo.alt='';
}

function clickclear(thisfield) {
		thisfield.value = "";
	if (thisfield.value == thisfield.defaultValue) {
		thisfield.value = "";
	}
}

function clickrecall(thisfield) {
	if (thisfield.value == "") {
		thisfield.value = thisfield.defaultValue;
	}
}

function switcher (img) {
	photo = document.getElementById('switcherPhoto');
	photo.src=img;
	photo.alt='';
}

var slideshowCurrent;
var slideshowImages;
function loadSlideshow () {
	slideshowCurrent = 0;
	slideshowImages  = document.getElementById("courseSlideshowImages").getElementsByTagName("img");
	slideshowButtonForward  = document.getElementById("slideshowGoForward");
	slideshowButtonBack  = document.getElementById("slideshowGoBack");
	if (slideshowImages.length != null) {
		document.getElementById("courseSlideshowImages").style.display = "none";
		document.getElementById("slideshowCurrentImage").style.backgroundImage="url("+slideshowImages[slideshowCurrent].src+")";
	}
	checkButtons();
}
function checkButtons() {
	if ((slideshowCurrent+1) < slideshowImages.length) {
		slideshowButtonForward.style.visibility = "visible";
	} else {
		slideshowButtonForward.style.visibility = "hidden";
	}
	if ((slideshowCurrent) > 0) {
		slideshowButtonBack.style.visibility = "visible";
	} else {
		slideshowButtonBack.style.visibility = "hidden";
	}
}
function slideshowGoForward() {
	if ((slideshowCurrent+1) < slideshowImages.length) {
		slideshowCurrent++;
		document.getElementById("slideshowCurrentImage").style.backgroundImage="url("+slideshowImages[slideshowCurrent].src+")";
	}
	checkButtons();
}
function slideshowGoBack() {
	if ((slideshowCurrent-1) >= 0) {
		slideshowCurrent--;
		document.getElementById("slideshowCurrentImage").style.backgroundImage="url("+slideshowImages[slideshowCurrent].src+")";
	}
	checkButtons();
}