Inline Table UDF does not accept table data

[dslr]

Hello All,

I have a simple TestFunction UDF

CREATE FUNCTION dbo.TestFunction ( @Idx int )
RETURNS @TestTabel TABLE  ( Idx int, Field1 int, Field2 int )
AS
BEGIN 
	INSERT @TestTabel ( Idx, Field1, Field2 )
	SELECT @Idx, 1, 2
	RETURN
END

Inserted in a query

SELECT TestFunction.Idx, TestFunction.Field1, TestFunction.Field2
FROM dbo.TestFunction(dbo.TempItems.ID) TestFunction INNER JOIN
     dbo.TempItems ON TestFunction.Idx = dbo.TempItems.ID

When I want to execute it Ill get the following message

Error in list of function arguments: '.' not recognized.
Incomplete parameters list.

So dbo.TempItems.ID is not axepted as an value but is interpreted as text

If I execute the query with a fixed value then it runs fine.

SELECT  TestFunction.Idx, TestFunction.Field1, TestFunction.Field2
FROM dbo.TestFunction(12) TestFunction INNER JOIN
     dbo.TempItems ON TestFunction.Idx = dbo.TempItems.ID

How do I get a table of numbers in it?

Regards,

Marco