function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images) {
		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) {
		Grid_06_over = newImage("images/Grid_06-over.gif");
		Grid_07_over = newImage("images/Grid_07-over.gif");
		Grid_08_over = newImage("images/Grid_08-over.gif");
		Grid_10_over = newImage("images/Grid_10-over.gif");
		Grid_11_over = newImage("images/Grid_11-over.gif");
		Grid_12_over = newImage("images/Grid_12-over.gif");
		Grid_13_over = newImage("images/Grid_13-over.gif");
		Grid_14_over = newImage("images/Grid_14-over.gif");
		Grid_15_over = newImage("images/Grid_15-over.gif");
		Grid_16_over = newImage("images/Grid_16-over.gif");
		Grid_17_over = newImage("images/Grid_17-over.gif");
		Grid_18_over = newImage("images/Grid_18-over.gif");
		Grid_19_over = newImage("images/Grid_19-over.gif");
		Grid_20_over = newImage("images/Grid_20-over.gif");
		Grid_21_over = newImage("images/Grid_21-over.gif");
		preloadFlag = true;
	}
}