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) {
		tab1_over = newImage("../images/tab1-over.gif");
		tab2_over = newImage("../images/tab2-over.gif");
		tab3_over = newImage("../images/tab3-over.gif");
		tab4_over = newImage("../images/tab4-over.gif");
		tab5_over = newImage("../images/tab5-over.gif");
		preloadFlag = true;
	}
}