agent = navigator.userAgent;
browserVer = 2;

if (agent.indexOf("a/3",6) == -1 & agent.indexOf("a/4",6) == -1) {
	browserVer = 2
}
else {
	browserVer = 3
}

function changeimg(img, name) {
	if (browserVer == 3) {
        document.images[name].src=img;
	}
}