browser_name = navigator.appName;
browser_version = parseFloat(navigator.appVersion); 

function turnon(x) {
	if (browser_name == "Netscape" && browser_version >= 3.0 || browser_name == "Microsoft Internet Explorer" && browser_version >= 4.0) {
		if (x == 1) {
			document.driveways.src = "/images/driveways_on.gif";
		}
		if (x == 2) {
			document.landscape.src = "/images/landscape_on.gif";
		}
		if (x == 3) {
			document.outcroppings.src = "/images/outcroppings_on.gif";
		}
		if (x == 4) {
			document.stone.src = "/images/stone_on.gif";
		}
		if (x == 5) {
			document.retaining.src = "/images/retaining_on.gif";
		}
	}
}

function turnoff(x) {
	if (browser_name == "Netscape" && browser_version >= 3.0 || browser_name == "Microsoft Internet Explorer" && browser_version >= 4.0) {
		if (x == 1) {
			document.driveways.src = "/images/driveways.gif";
		}
		if (x == 2) {
			document.landscape.src = "/images/landscape.gif";
		}
		if (x == 3) {
			document.outcroppings.src = "/images/outcroppings.gif";
		}
		if (x == 4) {
			document.stone.src = "/images/stone.gif";
		}
		if (x == 5) {
			document.retaining.src = "/images/retaining.gif";
		}
	}
}