Accepting datasets as parameters to webservice

[JeffC]

I've created a web service with a method that accepts a string and a dataset
as parameters. I've created the proxy class and written a .ASPX page to call
it. The code in the .ASPX loads some test data into the dataset and calls
the proxy class. The Web Service starts up, the string has the data from the
call in the .ASPX page, but the contents of the dataset parameter is
"Undefined." How can I see where the dataset got "lost"?