Transfering data between workbooks

ok I posted a small example Excel document.

Basically in sheet 2, I want the user to select the Plant and month from 2 drop down box lists (A2 and B2). Then the program should look in Sheet 1 columns D through C and copy the correct part number and it corresponding volume for that month.

So for example, If I select Findlay, March.

The program should return the part number 123BBB and a volume of 2156 in sheet 2.