countif question

[choice]

i have range (b2:b10000) that has part numbers (not unique)
i have range (a2:a10000) that has dates
column A is the date that column B was sold

I would like a countif or sumproduct function that says how many of Item X
were sold on X date. i would be putting the part number that i want to lookup
into C1 and the date that i want looked up in D1.

Thank you in advance

 

[Frank Kabel]

Hi
use
=SUMPRODUCT(--(A2:A10000=D1),--(B2:B10000=A1))

Also see:
http://www.xldynamic.com/source/xld.SUMPRODUCT.html