Linking data from 2 sheets

Hi,

I am using excel 2007, and have a question regarding formula - well I hope there is a formula for what I'm trying to achieve.

Basically I have 2 sheets in excel, the first sheet contains text messages imported from a phone and the second sheet is a list of contacts also imported from the phone.

My problem is that on the first sheet the 2nd column displays the phone number the message was sent or recieved to. I need if possible to change this into the name from the second sheet hopefully using a formula as there are thousands of rows I need to change.

The layout of the two sheets are as follows:

Sheet 1:

Column A = Date
Column B = Number - this is the number I need to find from the 2nd sheet
Column C = Sent
Column D = Who - I created a new column to make it easier so excel could put the name from sheet 2 in here rather than change column B
Column E = Text message

My data starts from cell A3

Sheet 2:

Column A = First name
Column B = Surname
Column C = Type of number
Column D = Phone number

Data starts from cell A3

If anyone can help it would be greatly appreciated as doing this manually will take forever!

Thanks
Josh