How do I insert text into empty xml element in sql server 2005?

Hello

I have the following xml data stored in an xml datatype colmun in sql
server 2005:

<webpage id="935623B3-F72D-45EE-AF88-47022F101184">
<createdate>Sep 6 2005 11:04AM</createdate>
<title>Themes</title>
<icon>app/16/p/text_align_left</icon>
<pagetext />
</webpage>

I'd like to be able to update the the xml so that there is text within
the pagetext element, i.e.

...
<pagetext>
Some content goes here.
</pagetext>
...

I've tried to achieve this using the query below:

update tbl_tree SET theTree.modify(' replace value of (//*[@.id=sql:variable("@.focusID")][1]/title/text())[1] with
sql:variable("@.someContent")')

but it doesn't work. Is this because you can't 'modify' an empty
element such as '<pagetext/>'

I thought about inserting a node such as '<pagetext>Some content goes
here.</pagetext>'- this would solve the problem only until such time as
the element has its contents removed at which point it will become
<pagetext/> again.

Is there a way to do this?

Any help very much appreciated.

For those interested, this has now been answered via a newsgroup here:
http://groups.google.com/group/microsoft.public.sqlserver.xml/browse_thread/thread/424e62d11c396b3e/bab10449576dccd8#bab10449576dccd8