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) {
		homebutton_over = newImage("images/homebutton-over.gif");
		aboutbutton_over = newImage("images/aboutbutton-over.gif");
		subbutton_over = newImage("images/subbutton-over.gif");
		edbutton_over = newImage("images/edbutton-over.gif");
		samplebutton_over = newImage("images/samplebutton-over.gif");
		mailbagbutton_over = newImage("images/mailbagbutton-over.gif");
		resourcebutton_over = newImage("images/resourcebutton-over.gif");
		greybar_homebutton_over = newImage("images/greybar-homebutton_over.gif");
		greybar_aboutbutton_over = newImage("images/greybar-aboutbutton_over.gif");
		greybar_subbutton_over = newImage("images/greybar-subbutton_over.gif");
		greybar_edbutton_over = newImage("images/greybar-edbutton_over.gif");
		greybar_samplebutton_over = newImage("images/greybar-samplebutton_over.gif");
		greybar_mailbagbutton_over = newImage("images/greybar-mailbagbutton_over.gif");
		greybar_resourcebutton_over = newImage("images/greybar-resourcebutton_over.gif");
		preloadFlag = true;
	}
}