window.onload = preloadImages;

function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

function swap_image(img_name, img_src, height, width) {
	if(document.images) {
		img = document[img_name];
		img.src = img_src;
		img.height = height;
		img.width = width;
	}
}

/*  wait a period of time before
	swapping the image
	delay_active is set to 1 when a swap is in progress
*/
var delay_active;
function swap_image_delay(img_name, img_src, height, width, delay) {
	delay_active=1;
	setTimeout("swap_image_delay_child('"+img_name+"','"+img_src+"',"+height+","+width+")",delay);
}

function swap_image_delay_child(img_name, img_src, height, width) {
	if(!delay_active) return;
	delay_active=0;
	if(document.images) {
		img = document[img_name];
		img.src = img_src;
		img.height = height;
		img.width = width;
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		artists_over = newImage("/ui/artists_over.gif");
		current_over = newImage("/ui/current_over.gif");
		upcoming_over = newImage("/ui/upcoming_over.gif");
		past_over = newImage("/ui/past_over.gif");
		inventory_over = newImage("/ui/inventory_over.gif");
		statement_over = newImage("/ui/statement_over.gif");
		location_over = newImage("/ui/location_over.gif");
		mailing_over = newImage("/ui/mailing_over.gif");
		preloadFlag = true;
	}
}