js basic 1

<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>Untitled Document</title>
</head>
<body>
<button onclick="cb('red')" onMouseOver="cb2(this,'red')" onMouseOut="cb2(this,'gray')">red</button>
<button onclick="cb('green')" onMouseOver="cb2(this,'green')" onMouseOut="cb2(this,'gray')">green</button>
<button onclick="cb('blue')" onMouseOver="cb2(this,'blue')" onMouseOut="cb2(this,'gray')">blue</button>
<script>
function cb(c){
	document.body.style.background = c;
}
function cb2(e,c){
	e.style.background = c;
}
var ua=navigator.userAgent;
document.write(ua);
document.body.style.background = "#0F0";
</script>
</body>
</html>