<body>
<p>You should see two "PASS" messages below:</p>

<script>
if (window.layoutTestController)
  layoutTestController.dumpAsText();

document.write("Computed style parent (should be null): " + document.defaultView.getComputedStyle(document.body, null).parentRule);
try {
  document.defaultView.getComputedStyle(document.body, null).color = "blue";
  document.write("<p>FAIL: did not get an exception when trying to change a computed style declaration.");
} catch (ex) {
  document.write("<p>PASS: got an exception when trying to change a computed style declaration, " + ex);
}

try {
  document.defaultView.getComputedStyle(document.body, null).setProperty("color", "blue");
  document.write("<p>FAIL: did not get an exception when trying to change a computed style declaration via setProperty.");
} catch (ex) {
  document.write("<p>PASS: got an exception when trying to change a computed style declaration via setProperty, " + ex);
}

</script>
</body>