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) {
		 welcome = newImage("images/nav_welcome_hl.gif");
		 cosmetic = newImage("images/nav_cosmetic_dentistry_hl.gif");
		 advanced = newImage("images/nav_advanced_technology_hl.gif");
		 general = newImage("images/general_dentistry_hl.gif");
		 contact = newImage("images/contact_hl.gif");
		preloadFlag = true;
	}
}

//preload images for building swap first
img1=new Image()
img1.src="images/projects/p1_main1.jpg"
img2=new Image()
img2.src="images/projects/p1_main2.jpg"
img3=new Image()
img3.src="images/projects/p1_main3.jpg"
img4=new Image()
img4.src="images/projects/p1_main4.jpg"
img5=new Image()
img5.src="images/projects/p1_main5.jpg"