simple lookup formula?

This should be simple, but I'm suffering form a mental block. Please help me.

I need to look up in a table the availability of an item.
This table contains available quantities for every item in 3 different warehouses.

For example:

I like to see how many pencils are available in warehouse No. 3

The structure of the stock file is as follows:

Item WH Qty

Pencils 01 0
Erasers 01 1
Clips 01 5
Staples 01 2
Pencils 02 5
Erasers 02 4
Clips 02 5
Staples 02 2
Pencils 03 5
Erasers 03 0
Clips 03 5
Staples 03 2