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) {
		/*navppm = newImage("images/nav_ppm-over.gif");
		navba = newImage("images/nav_ba-over.gif");
		navrm = newImage("images/nav_rm-over.gif");
		navpptools = newImage("images/nav_pptools-over.gif");
		navtraining = newImage("images/nav_training-over.gif");
		navpom = newImage("images/nav_pom-over.gif");*/
		preloadFlag = true;
	}
}