Hi,,,, solve my headache

I have 2 sheets within excel. i need a formula that will check the
names from 2 sheets, if it has the same name then it will enter into
sheet2 column G the contact number ( Sheet 1 - column C)

How the spread sheet is setup at the min!!
Sheet 1! In column A I have Surname - column B I have first name -
column C contact Number.
Sheet 2! In column A first name - column B surname.


TIA
Much appreciate any help