Multi condition lookup

It is coded to return blanks where there is no match. For example there is no part# 1000 nor 1659 in the sample. Also the dates listed in the sample are January through May, so it returns blanks for June through December. I tested it with your sample and it returns the quantity for part#'s and months listed in O1:Q24

Correct, however it is returning blanks for value that are there and should show up. Am I using your formula the right way?
Book2.xlsx