function preloadImages(relRoot) {
	if (objHoverStories) {
		objHoverStories.src = relRoot + "images/nav_stories_on.gif";
	}
	if (objHoverResponses) {
		objHoverResponses.src = relRoot + "images/nav_responses_on.gif";
	}
	if (objHoverGlossary) {
		objHoverGlossary.src = relRoot + "images/nav_glossary_on.gif";
	}
	if (objHoverActivities) {
		objHoverActivities.src = relRoot + "images/nav_activities_on.gif";
	}
	if (objStories) {
		objStories.src = relRoot + "images/nav_stories_off.gif";
	}
	if (objResponses) {
		objResponses.src = relRoot + "images/nav_responses_off.gif";
	}
	if (objGlossary) {
		objGlossary.src = relRoot + "images/nav_glossary_off.gif";
	}
	if (objActivities) {
		objActivities.src = relRoot + "images/nav_activities_off.gif";
	}
}

function preloadPopupImages(relRoot) {
	for (var i = 0; i < 18; i++) {
		faceArray[i] = new Image(123, 71);
	}
	if (faceArray[0]) {
		faceArray[0].src = relRoot + "images/transcripts_photo_amna.jpg";
	}
	if (faceArray[1]) {
		faceArray[1].src = relRoot + "images/transcripts_photo_anjum.jpg";
	}
	if (faceArray[2]) {
		faceArray[2].src = relRoot + "images/transcripts_photo_golzar.jpg";
	}
	if (faceArray[3]) {
		faceArray[3].src = relRoot + "images/transcripts_photo_jihad.jpg";
	}
	if (faceArray[4]) {
		faceArray[4].src = relRoot + "images/transcripts_photo_khaled.jpg";
	}
	if (faceArray[5]) {
		faceArray[5].src = relRoot + "images/transcripts_photo_kinya.jpg";
	}
	if (faceArray[6]) {
		faceArray[6].src = relRoot + "images/transcripts_photo_kiyo.jpg";
	}
	if (faceArray[7]) {
		faceArray[7].src = relRoot + "images/transcripts_photo_maher.jpg";
	}
	if (faceArray[8]) {
		faceArray[8].src = relRoot + "images/transcripts_photo_marion.jpg";
	}
	if (faceArray[9]) {
		faceArray[9].src = relRoot + "images/transcripts_photo_muhammed.jpg";
	}
	if (faceArray[10]) {
		faceArray[10].src = relRoot + "images/transcripts_photo_ruth.jpg";
	}
	if (faceArray[11]) {
		faceArray[11].src = relRoot + "images/transcripts_photo_satsuki.jpg";
	}
	if (faceArray[12]) {
		faceArray[12].src = relRoot + "images/transcripts_photo_sayema.jpg";
	}
	if (faceArray[13]) {
		faceArray[13].src = relRoot + "images/transcripts_photo_shig.jpg";
	}
	if (faceArray[14]) {
		faceArray[14].src = relRoot + "images/transcripts_photo_sho.jpg";
	}
	if (faceArray[15]) {
		faceArray[15].src = relRoot + "images/transcripts_photo_ted.jpg";
	}
	if (faceArray[16]) {
		faceArray[16].src = relRoot + "images/transcripts_photo_toru.jpg";
	}
	if (faceArray[17]) {
		faceArray[17].src = relRoot + "images/transcripts_photo_tosh.jpg";
	}
}

function preloadIntroImages(relRoot) {
	if (objHoverBegin) {
		objHoverBegin.src = relRoot + "images/intro_begin_on.gif";
	}
	if (objBegin) {
		objBegin.src = relRoot + "images/intro_begin_off.gif";
	}
}

var currentImageIndex = 1;

function rotateFaces() { 
	swapImage('currentSubject', faceArray[currentImageIndex]);
	currentImageIndex++;
	if (currentImageIndex >= faceArray.length) {
		currentImageIndex = 0;
	}
}

function displayFace(img) {
	stopLoop();
	swapImage('currentSubject', img);
}

function goLoop() {
	while (rotateFaceLoopId) {
		stopLoop();
	}
	rotateFaceLoopId = window.setInterval("rotateFaces();", 1000);
}

function stopLoop() {
	window.clearInterval(rotateFaceLoopId);
	rotateFaceLoopId = false;
}

function swapImage(strElement, objImage) 
{
	// check if the objects exists to prevent errors
	if (document.images && objImage && objImage.src && objImage.src != "") 
	{
		if (document.images[strElement]) 
		{
			document.images[strElement].src = objImage.src
		}
	}
}

function popTranscript() {
	transcriptWindow = window.open('stories/popup.html','transcriptPopup','width=580,height=340,toolbar=1,location=0,directories=0,status=0,menubar=1,scrollbars=1,resizable=1');
}

function popCredits(relroot) {
	creditsWindow = window.open(relroot + 'credits/','creditsPopup','width=580,height=340,toolbar=1,location=0,directories=0,status=0,menubar=1,scrollbars=1,resizable=1');
}

function popMap() {
	mapWindow = window.open('../glossary/map.html','mapPopup','width=785,height=500,toolbar=1,location=0,directories=0,status=0,menubar=1,scrollbars=0,resizable=1');
}

function popLesson(filename) {
	lessonWindow = window.open('../activities/' + filename,'lessonPopup','width=590,height=500,toolbar=1,location=0,directories=0,status=0,menubar=1,scrollbars=1,resizable=1');
}

function popPlayer(filename, fullname, firstname, subject, quote) {
	playerWindow = window.open('../stories/player.html?file=' +  filename + '&fullname=' + fullname+ '&firstname=' + firstname + '&subject=' + subject + '&quote=' + quote,'audioPopup','width=360,height=120,toolbar=0,location=0,directories=0,status=0,menubar=0,scrollbars=1,resizable=0');
}

function setParentLocation(popupWindow, location) {
	if (popupWindow.opener && !popupWindow.opener.closed) {
		popupWindow.opener.location = location;
	} else {
		lessonWindow = window.open(location,'sitePopup','width=800,height=600,toolbar=1,location=1,directories=1,status=1,menubar=1,scrollbars=1,resizable=1');
	}
}