<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link rel="icon" src="/images/favicon.gif" />
<title>test</title>
<script type="text/javascript">
function slice (x) { return Array.prototype.slice.call(x); }
var controls;
onload = function () {
controls = slice(document.getElementsByTagName("label"));
controls = controls.concat(slice(document.getElementsByTagName("button")));
console.log(controls);
}
</script>
</head>
<body>
<label>label</label>
<button>button</button>
</body>
</html>