I took the liberty to move this thread, since I found it of very little use in the feedback section.
To me it looks like some VB program, but without the [ code][/ code] tags surrounding it I can't realy read the code that well.
Code:
... IIf([Invoice_Date]<Now()-30 And [Invoice_DATE]>Now()-60,[Invoice_Amount],"")
AS Greaterthan30,
IIf([Invoice_Date]<Now()-60,[Invoice_Amount],"")
AS Greaterthan60 ...
Thats the SQL-limitation, you are trying to fetch from the same field into two different arguments.
This sounds alot like some homework...