how do i link data from one sheet to another if value keep changin
 

I have 2 worksheets called sheet1 and sheet2. i have 2 columns called Order #
and Division. Now i want to setup sheet2 so that it shows the same value as
what Order# and Division has in sheet1. But what if there are 2 or more
instances of Order# per one Division?
Let me demonstrate:
Sheet1 holds this info ( assuming the heading Order # is in cell A1 and
Division in cell B1 and so on...):
Order# Division
123 ABC
456 ABC
789 DEF
789 EFG

How should i code my formulas? thatnks for all the help