SQL Server 2008 :: Export Tree Data To XML

I am trying to output the hierarchical data of a tree to xml format.

I can query the data from the tables into a friendly format like this:

create table dummy
(
id int,
childname nvarchar(max),
parentid int,
parentname nvarchar(max)

[Code] ....

And I always know the root ID from the first record on "table" dummy (generated with a common table expression), in this case it's ID 1, but from here, how to process this for any level of depth ?