Counting the number of instances of a code in a certain week

I'm analysing sales data, and our system outputs Week number followed by the order code.

What I'm trying to do is to find out the number of separate instances that a product is ordered in a week.
The report looks like this:

Week no Code
1 SAR0001
1 SAR0001
1 SAR0002
1 XQL0001
1 XQL0001
1 XQL0001
1 XQR0001
1 XQR0001
1 XQR0001
1 XQR0001
1 XQR0001
1 XQR0001
1 XQR0001

and the weeks increase down the page.

I tried using

=COUNTIF(B:B,AND(N2,M2))

Where N2 is the week number and M2 is the code I want to match, but it doesn't seem to work.

Can anyone help?

Many thanks,

Chris

Try..

=SUMPRODUCT(--($A$2:$A$13=N2),--($B$2:$B$13=M2))

Note that SUMPRODUCT does not accept whole column references.

Hope this helps!

That does exactly what I was after - many thanks!

Chris