How to use linq dataContext methods from stored procs

[Andy B]

I have a stored proc that selects all from a database table. I drug it from
the server explorer onto the o/r designer to make it part of the
dataContext. Now I can't figure out how to use it. I don't think I know how
to use the ISingleResult type since that is what it returns from what I can
see. Any examples of how to do this? any examples I can find are either
incomplete, or bad examples. The dataContext is called TestXmlDataCont ext,
the entity class is called TestXml and the dataContext method is called
SelectAll. I let vs2008 auto pick the return type.