Macro or formuale help required comparing cel

Hello,
I've got Excel 2003 with 2 columns of data A & B with people names in it. Column A is always populated with data (a name), column B isn't always populated (with a name) its either present or not.

I've got to a point whereby if there is nobodys name in a row cell for column B (i.e. its an empty cell) I want the contents to the right of that particular cell (i.e. persons name in column A) copied to another column i.e. C

Its probably simple but I'm not sure how to do this so any help would be appreciated.

Many thanks
NT