testSheet should initially be empty");
      sheet.insertRule("@font-face { src: " + t.src + "}");
      try {
        assert_equals(sheet.cssRules[0].style.getPropertyValue("src") != "", t.valid);
      } finally {
        sheet.deleteRule(0);
      }
    }, "Check that src: " + t.src + " is " + (t.valid ? "valid" : "invalid"));
  }
</script>
