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) {
		Button1_over = newImage("img/prof1_over.gif");
		Button2_over = newImage("img/prof2_over.gif");
		Button3_over = newImage("img/prof3_over.gif");
		Button4_over = newImage("img/prof4_over.gif");
		Button5_over = newImage("img/prof5_over.gif");
		Button6_over = newImage("img/prof6_over.gif");
		Button7_over = newImage("img/prof7_over.gif");
		Button8_over = newImage("img/prof8_over.gif");
		Button9_over = newImage("img/prof9_over.gif");
		Button10_over = newImage("img/prof10_over.gif");
		Button11_over = newImage("img/prof11_over.gif");
		Button12_over = newImage("img/prof12_over.gif");
		preloadFlag = true;
	}
}