<!DOCTYPE html>
<html>
<head>
<script>

function boom()
{
    var a = document.createElement("select");
    var f = document.createElement("optgroup");
    var g = document.createElement("optgroup");
    a.appendChild(f);
    g.appendChild(document.createElement("option"));
    f.appendChild(g);
    a.appendChild(document.createElement("option"));
    document.body.appendChild(a);
}

</script>
</head>
<body onload="boom();"></body>
</html>