Thanks I fixed that and now it is running. Do you know how I can get the results for both the 'Delivered' and 'Returned' quantities to display on the same line?
SELECT T0.[ITEMCODE], NULL AS 'Delivered', sum(T0.[Quantity]) AS 'Returned'
FROM RDN1 T0
INNER JOIN ORDN T1 on T0.DocEntry = T1.DocEntry
WHERE T1.[DocDate] >=[%0] and T1.[DocDate] <=[%1]
GROUP BY T0.[ITEMCODE], T0.Quantity
UNION
SELECT T2.[ITEMCODE], sum(T2.[Quantity]) AS 'Delivered', NULL AS 'Returned'
FROM ODLN T3
INNER JOIN DLN1 T2 on T2.DocEntry = T3.DocEntry
WHERE T3.[DocDate] >=[%0] and T3.[DocDate] <=[%1]
GROUP BY T2.[ITEMCODE], T2.Quantity