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];
			}
		}
	}
	
	var preloadFlag = false;
	function preloadImages() {
		if (document.images) {
			header_home_button_1_over = newImage("images/header_home_button_1_over.gif");
			header_home_button_2_over = newImage("images/header_home_button_2_over.gif");
			header_home_button_3_over = newImage("images/header_home_button_3_over.gif");
			header_home_button_4_over = newImage("images/header_home_button_4_over.gif");
			header_home_button_5_over = newImage("images/header_home_button_5_over.gif");
			header_home_button_6_over = newImage("images/header_home_button_6_over.gif");
			side_nav_button_1_over = newImage("images/side_nav_button_1_over.gif");
			side_nav_button_2_over = newImage("images/side_nav_button_2_over.gif");
			side_nav_button_3_over = newImage("images/side_nav_button_3_over.gif");
			side_nav_button_4_over = newImage("images/side_nav_button_4_over.gif");
			side_nav_button_5_over = newImage("images/side_nav_button_5_over.gif");
			preloadFlag = true;
		}
	}