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) {
		home = newImage("images/nav_home_on.gif");
		 about = newImage("images/nav_about_on.gif");
		 casestudies = newImage("images/nav_casestudies_on.gif");
		 clients = newImage("images/nav_clients_on.gif");
		 contact = newImage("images/nav_contact_on.gif");
		 
		 preloadFlag = true;
	}
}

//preload images for building swap first
img1=new Image()
img1.src="images/featured_pic1_on.gif"