Lookups in Excel

Hello,

I am trying to create a merge document for a mailing list for a rewards program we run at work. In one document I have the person's details and the number of points they have earned and in another I have a list of points and their appropriate prizes. What I want to do is find the highest level of prize they would be entitled to claim with their current level of points and have it returned as a value in a colum of the original document. Can someone please help me?

eg:

Spreadsheet A

Name | Address | Points
Joe | 123 Street| 590
Mary | 12 Street| 10050

Spreadsheet B

Points | Prize
500 | $50 Voucher
750 | $75 Voucher
2000 | Holiday
10000 | Camera
15000 | Laptop

Joe's should return a $50 voucher and Mary's should return as a camera.