FOR XML AUTO Question

Hi,
I have the following sample code:

CREATE PROCEDURE SomeProc
AS
BEGIN
SET NOCOUNT ON;

SELECT Employees.EmployeeID, Employees.LastName, Employees.FirstName,
Orders.OrderID, Orders.OrderDate, Orders.EmployeeID
FROM Orders INNER JOIN Employees ON Orders.EmployeeID = Employees.EmployeeID
ORDER BY Employees.EmployeeID ASC
FOR XML AUTO
END
GO

which provides some output in xml format.
What i want to do is to return the xml output in a variable, so as to use it after that.
if i use the following:


declare @retXml navrchar(200)
exec @retXml=SomeProc
select @retXml

it complaints tha the result must be an integer!How can i take the xml result in a variable?