Hi Miguel

With your data on Sheet1, Dates in column A, Vendor in column B, and row
1 as a header.
On Sheet2 with Date require entered in A1 and Vendor required in B1,
enter in C1
=SUMPRODUCT(--(Sheet1!$A$2:$A$100<=A1),--(Sheet1!$B$2:$B$100=B1))

--
Regards

Roger Govier


"Miguel" wrote in message
...
I need to make a formula which will add all items in another tab which
are
less than 11/30/05 and have the same vendor