I need to be able to convert city abbreviations ex: CHI to Chicago, IL. The way I have it set up in spreadsheets right now is:

I have on Worksheet 1 - in Column A, Row 1 = CHI
in Column B, Row 1 = Chicago, IL
in Column A, Row 2 = ATL
in Column B, Row 2 = Atlanta, GA. and so on....

On Worksheet 2 -

This worksheet is my lane worksheet where I have an Origin and Destination
- in Column A, Row 1 = CHI (origin)
- in Column B, Row 1 = ATL (destination)



I need a formula that will convert the abbreviation cities into the full name cities, this will need to convert them so I can pull them into a "worksheet 3"....

ex: - in Column A, Row 1 = Chicago, IL
- in Column B, Row 1 = Atlanta, GA

Thanks,

Scott