Thread: Enter Parameter Value

Hi, i have written the following query in access which gives me an "Enter Parameter Value" Popup for SumOfWorkload and SumOfNumber Of OM. Can anybody help me understand why this is.

SELECT [13WeeksData].GM, [13WeeksData].[Friendly Queue Name], Sum([13WeeksData].[Number Of OM]) AS [SumOfNumber Of OM], Sum([13WeeksData].Workload) AS SumOfWorkload, [13WeeksData].[Week Start Date], ([SumOfWorkload]/[SumOfNumber Of OM]) AS AHT INTO 13WeeksData_GM_Table
FROM 13WeeksData
GROUP BY [13WeeksData].GM, [13WeeksData].[Friendly Queue Name], [13WeeksData].[Week Start Date], ([SumOfWorkload]/[SumOfNumber Of OM])
ORDER BY [13WeeksData].GM;

Thanks in advance.