SVG

gistfile1.xml

<svg xmlns="http://www.w3.org/2000/svg" onload="func(evt)">
<script>
function func(evt) {
    var ns = "http://www.w3.org/2000/svg";
    var doc = evt.target.ownerDocument;
    var circle = doc.createElementNS(ns, 'circle');
    circle.setAttributeNS(null, 'cx', '100');
    circle.setAttributeNS(null, 'cy', '100');
    circle.setAttributeNS(null, 'r', '50');
    doc.documentElement.appendChild(circle);
}
</script>
<rect x="10" y="10" width="100" height="100" />
</svg>