//Javascripts for the home page

//go to a URL chosen from a pull-down menu
function jump(menu) {
	var u=menu.options[menu.selectedIndex].value;
	if(u != '') {
		document.location=u;
	}
	
	return false;
}

var cycledir = false;
var cyclecount = 0;
//duration in seconds
var cycleduration = 5;
var cyclestarted = false;

function cycleImage() {
	imageInfo = cyclelist[cyclecount];

	//is this a string (which means we only change the image source)
	//or an array (which means we change both the image source and the href)
	if (typeof imageInfo == "string") {
		imageSRC = imageInfo;
	} else {
		backgroundImage = imageInfo[0];
		imageSRC = imageInfo[1];
		imagelink = imageInfo[2];
		cyclelink = cycletarget.parentNode;
		cyclelink.href = imagelink;
	} 

	if (imageSRC) {
		cycletarget.style.display="inline";
		if (cycledir) {
			imageSRC = cycledir + imageSRC;
		}
		cycletarget.src=imageSRC;
	} else {
		cycletarget.style.display="none";
	}

	if (backgroundImage) {
		backgroundImage = "http://www.sandiego.edu/" + cycledir + backgroundImage;
		var backgroundImage = "url(" + backgroundImage + ")";
		
		var featureDiv = document.getElementById("feature-wrapper");
		featureDiv.style.backgroundImage = backgroundImage;
	}

	cyclecount++;
	if (cyclecount == cyclelist.length) {
		cyclecount = 0;
	}
	setTimeout("cycleImage()", cycleduration*1000);
}

function cycleMe(image, duration, imagelist, imagedir) {
	preloadedImages = new Array();
	for(var i=0;i<imagelist.length;i++) {
		var imageInfo = imagelist[i];
		var bgImage = imageInfo[0];
		if (bgImage) {
			bgImage = "http://www.sandiego.edu/" + cycledir + bgImage;
			var imageLoader = new Image();
			imageLoader.src = bgImage;
			preloadedImages.push(imageLoader);
		}
	}

	if (!cyclestarted) {
		cyclestarted = true;

		cycletarget = image;
		if (imagelist) {
			cyclelist = imagelist;
		}
		if (imagedir) {
			cycledir = imagedir;
		}
		if (duration) {
			cycleduration = duration;
		}
		cycleImage();
	}
}