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

if (browser_name == "Netscape" && browser_version >= 3.0) {
	roll = 'true';
	}

else if (browser_name == "Microsoft Internet Explorer" && browser_version >= 4.0) {
	roll = 'true';
	}

function msover(img1,ref1) {
	if (roll == 'true') {
		document.images[img1].src = ref1;
		}
	}
        
function msout(img1,ref1) {
	if (roll == 'true') {
		document.images[img1].src = ref1;
		}
	}