diff --git a/mozilla/extensions/python/dom/test/pyxultest/pytester.py b/mozilla/extensions/python/dom/test/pyxultest/pytester.py
index f3a2c1ad513..bc7d6367ef1 100644
--- a/mozilla/extensions/python/dom/test/pyxultest/pytester.py
+++ b/mozilla/extensions/python/dom/test/pyxultest/pytester.py
@@ -1,14 +1,79 @@
-# Runs non-ui related test code.
+# Runs test code in a UI environment.  Generally anything which can be tested
+# without visual confirmation is suitable for running here.
+# Note too that the simple fact we *can* display a UI and run tests is
+# exercising lots of things.
+import sys
 from xpcom import components
 import xpcom
 
-def do_onload():
-    # Why can't I get args??
-    # Intention is to look at window.arguments and determine what 'test'
-    # we are being asked to run.
-    print "OnLoad called"
-    raise "foo"
+close_on_success = True
 
-def do_onerror(*arguments):
-    print "OnError called"
-    print "Args are", arguments
+# Utility functions
+# Write something to the textbox - eg, error or trace messages.
+def write( msg, *args):
+    tb = this.document.getElementById("output-box")
+    val = tb.getAttribute("value")
+    val += (msg % args) + "\n"
+    tb.setAttribute("value", val)
+
+def success():
+    # This gets called if the test works.  If it is not called, it must not
+    # have worked :)
+    write("The test worked!")
+    if close_on_success:
+        print "Closing the window - nothing interesting to see here!"
+        window.close()
+
+def cause_error():
+    write("Raising an error")
+    raise "Testing Testing"
+
+def handle_error_with_cancel(errMsg, source, lineno):
+    success()
+
+def test_error_explicit():
+    "Test an explicit assignment of a function object to onerror"
+    # Assign a function to an onerror attribute
+    write("Assigning a function to window.onerror")
+    window.onerror = handle_error_with_cancel
+    cause_error()
+
+def test_error_explicit_string():
+    "Test an explicit assignment of a string to onerror"
+    # Assign a string to an onerror attribute
+    write("Assigning a string to window.onerror")
+    window.onerror = "handle_error_with_cancel(event, source, lineno)"
+    cause_error()
+
+class EventListener:
+    _com_interfaces_ = components.interfaces.nsIDOMEventListener
+    def handleEvent(self, event):
+        write("nsIDOMEventListener caught the event")
+        success()
+
+def test_error_eventhandler():
+    """Test we can explicitly hook the error with our own nsIDOMEventListener"""
+    write("Creating an nsIDOMEventListener to listen for the event")
+    window.addEventListener("onerror", EventListener(), False)
+    write("For some reason 'onerror' is not working.  Onload appears to?")
+    write("I need to check out if this works from JS first")
+    cause_error()
+    
+# The general event handlers and test runner code.
+def do_onload(event):
+    global close_on_success
+    klasses = []
+    if len(this.arguments) and this.arguments[0]:
+        try:
+            func = globals()[this.arguments[0]]
+        except KeyError:
+            print "*** No such test", this.arguments[0]
+            func = None
+    else:
+        func = test_error_explicit_string
+        close_on_success = False
+    if len(this.arguments)>1 and this.arguments[1]=="-k":
+        close_on_success = False
+    if func:
+        write(func.__doc__ or func.__name__)
+        func()
diff --git a/mozilla/extensions/python/dom/test/pyxultest/pytester.xul b/mozilla/extensions/python/dom/test/pyxultest/pytester.xul
index 33355a52c3b..31b65f48d87 100644
--- a/mozilla/extensions/python/dom/test/pyxultest/pytester.xul
+++ b/mozilla/extensions/python/dom/test/pyxultest/pytester.xul
@@ -2,7 +2,8 @@
 <?xml-stylesheet href="chrome://communicator/skin/" type="text/css"?>
 
 <!-- A container for general test code.  Relies on being passed an argument
-     for which test to run
+     for which test to run.  Generally it runs the test and closes, only
+     staying open when something goes wrong.
 -->
  
 <window
@@ -11,14 +12,16 @@
   screenX="100" screenY="100"
   height="300" width="500"
   script-type="application/x-python"
-  onload="do_onload()" onerror="do_onerror(event, source, lineno)"
+  onload="do_onload(event)"
+  onunload="print 'The test runner form is unloading'"
+  title="Test Runner"
   >
   <script src="chrome://pyxultest/content/pytester.py"/>
   <script type="application/javascript">
-dump('hello from js\n');
-function x_onload() {
-    dump('JS Args are' + window.arguments + '\n');
-}
-//window.onload = onload;
+dump('hello from js with args ' + window.arguments.length + '\n');
   </script>
+  <textbox id="output-box" style="width:100%" value = ""
+           rows="15" multiline="true" flex="1"
+  />
+  
 </window>
diff --git a/mozilla/extensions/python/dom/test/pyxultest/pyxultest.py b/mozilla/extensions/python/dom/test/pyxultest/pyxultest.py
index 4bf502dce65..1c794b23042 100644
--- a/mozilla/extensions/python/dom/test/pyxultest/pyxultest.py
+++ b/mozilla/extensions/python/dom/test/pyxultest/pyxultest.py
@@ -3,10 +3,18 @@
 import sys
 import xpcom
 from xpcom import components
+import nsdom
 
-# This EventListener class is to work around the fact that
-# addEventListener can not automagically wrap a string or function like
-# JS can.
+# Utility functions
+# Write something to the textbox - eg, error or trace messages.
+def write( msg, *args):
+    tb = this.document.getElementById("output_box")
+    val = tb.getAttribute("value")
+    val += (msg % args) + "\n"
+    tb.setAttribute("value", val)
+
+# An event listener class to test explicit hooking of events via objects.
+# Note Python can now just call addEventListener a-la JS
 class EventListener:
     _com_interfaces_ = components.interfaces.nsIDOMEventListener
     def __init__(self, handler, globs = None):
@@ -22,22 +30,25 @@ class EventListener:
 # An event function to handle onload - but hooked up manually rather than via
 # having the magic name 'onload'
 def do_load():
-    input = this.document.getElementById("input-box")
-    val = "This is the Python on XUL demo using\nPython " + sys.version
-    input.setAttribute("value", val)
-    
-    # Sadly no inline event handlers yet - hook up a click event.
-    button = this.document.getElementById("button1")
-    button.addEventListener('click', EventListener('print "hello from the click event"'), False)
+    input = this.document.getElementById("output_box")
+    # Clear the text in the XUL
+    input.setAttribute("value", "")
+    write("This is the Python on XUL demo using\nPython " + sys.version)
 
-# Add the event listener.
-this.window.addEventListener('load', EventListener(do_load), False)
+    # Sadly no inline event handlers yet - hook up a click event.
+    button = this.document.getElementById("but_dialog")
+    button.addEventListener('click', 'write("hello from the click event for the dialog button")', False)
+
+# Add an event listener as a function
+this.window.addEventListener('load', do_load, False)
 # Add another one just to test passing a string instead of a function.
-this.window.addEventListener('load', EventListener('print "hello from the event " + str(this.document)'), False)
+this.window.addEventListener('load', "print 'hello from string event handler'", False)
+# And yet another with an explicit EventListener instance. (on error tests can't do this?)
+this.window.addEventListener('load', EventListener('print "hello from an object event handler"'), False)
 
 # Some other little functions called by the chrome
-def on_button_click():
-    print "Button clicked from", this.window.location.href
+def on_but_dialog_click():
+    write("Button clicked from %s" %  this.window.location.href)
     # window.open doesn't work as JS has special arg handling :(
     # for now, use our hacky (but quite wonderful) JSExec function.
     import nsdom
@@ -45,8 +56,19 @@ def on_button_click():
     #new = this.window.open("chrome://pyxultest/content/dialog.xul", "my-dialog", "chrome")
     #print "The new window is", new
 
-def test_error_event():
-    import nsdom
-    nsdom.JSExec(this, 'this.window.openDialog("chrome://pyxultest/content/pytester.xul", "my-dialog", "modal", "test_error_event")')
-    #new = this.window.open("chrome://pyxultest/content/dialog.xul", "my-dialog", "chrome")
-    #print "The new window is", new
+def run_tests():
+    tests = """test_error_explicit test_error_explicit_string
+                test_error_eventhandler""".split()
+    keep_open = this.document.getElementById("keep_tests_open").getAttribute("checked")
+    for test in tests:
+        write("Running test %s" % test)
+        suffix = ', "%s"' % test
+        if keep_open:
+            suffix += ', "-k"'
+        cmd = 'this.window.openDialog("chrome://pyxultest/content/pytester.xul", "my-dialog", "modal"%s)' % suffix
+        print "cmd is", cmd
+        nsdom.JSExec(this, cmd)
+    if keep_open:
+        write("Ran all the tests - the windows told you if the tests worked")
+    else:
+        write("Ran all the tests - if you saw no window, it worked!")
diff --git a/mozilla/extensions/python/dom/test/pyxultest/pyxultest.xul b/mozilla/extensions/python/dom/test/pyxultest/pyxultest.xul
index 19b5071c81b..00d11226feb 100644
--- a/mozilla/extensions/python/dom/test/pyxultest/pyxultest.xul
+++ b/mozilla/extensions/python/dom/test/pyxultest/pyxultest.xul
@@ -8,9 +8,10 @@
   xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
   id="main-window" orient="vertical"
   screenX="100" screenY="100"
-  height="300" width="500"
+  height="450" width="600"
   script-type="application/x-python"
   onload="print 'hello from the window load event'"
+  title="Python in XUL demos and tests"
   >
   <script type="application/x-python" src="chrome://pyxultest/content/pyxultest.py"/>
   <script>
@@ -27,23 +28,45 @@ print "Window location is", this.window.location.href
     ]]>
   </script>
   <vbox flex="1">
-    <textbox id="input-box" style="width:100%" value = "hello there"
-             rows="5" multiline="true" flex="1"
+    <textbox id="output_box" style="width:100%"
+             value = "If you can see this, things aren't working well!"
+             rows="15" multiline="true" flex="1"
     />
-    <button id="button1" label="open dialog"
-            oncommand="on_button_click()"/>
   </vbox>
-  <!-- A box from our overlay - it will have one button using js events
-       and another using Python events -->
-  <hbox id="language_box"/>
-  
-  <button id="but_multi" label="click for both"/>
-  <!-- Here we have a script element defined at a parent node -->
-  <hbox oncommand="print 'You clicked on a', event.target.tagName">
-    <button label = "click here"/>
-    <button label = "or here"/>
-    <button id="test_error" label="test error event" oncommand="test_error_event()"/>
 
-  </hbox>
+  <groupbox>
+    <caption label="Items from Overlays"/>
+    <!-- A box from our overlay - it will have one button using js events
+         and another using Python events -->
+    <hbox>
+      <hbox id="language_box"/>
+      <button id="but_multi" label="click for both"/>
+    </hbox>
+  </groupbox>
+
+  <groupbox>
+    <caption label="Random Buttons"/>
+  
+    <hbox>
+      <!-- Here we have a script element defined at a parent node -->
+      <hbox oncommand="write('You clicked on a %s with id=%s' % (event.target.tagName, event.target.getAttribute('id')))">
+        <button id="some-button" label = "click here"/>
+        <button id="another-button" label = "or here"/>
+      </hbox>
+      <button id="but_dialog" label="open dialog"
+              oncommand="on_but_dialog_click()"/>
+    </hbox>
+  </groupbox>
+
+  <groupbox>
+    <caption label="Automated tests"/>
+    <hbox>
+      <button id="test_error" label="Run tests" oncommand="run_tests()"/>
+      <vbox flex="1">
+        <text class="label" value="The test window is not shown if the tests are successful"/>
+        <checkbox id="keep_tests_open" label="Always keep test window open"/>
+      </vbox>
+    </hbox>>
+  </groupbox>
 </window>