.prefix, null);
  assert_equals(element.localName, "span");
  assert_equals(element.tagName, "span");
  assert_true(element instanceof Node, "Should be a Node");
  assert_true(element instanceof Element, "Should be an Element");
  assert_false(element instanceof HTMLElement, "Should not be an HTMLElement");
  assert_false(element instanceof HTMLSpanElement, "Should not be an HTMLSpanElement");
}, "undefined namespace");

test(function() {
  var element = document.createElementNS("", "span");
  assert_equals