function getData(doc,ename) {
  var ns = 'http://www.goat1000.com/svggraph', element;
  element = doc.getElementsByTagName('svggraph:' + ename);
  if(!element.length)
    element = doc.getElementsByTagNameNS(ns, ename);
  if(!element.length)
    return null;
  return element[0];
}
