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) {
		menu_over = newImage("/images/menu_left_highlight.gif");
        menu_overb = newImage("/images/menu_right_highlight.gif");
        menu_overc = newImage("/images/bg_data_cell_active.gif");
        menu_overc = newImage("/images/menu_bg_active.gif");
		preloadFlag = true;
	}
}