Track all the changes of all the columns in respective rows of column A

Hi,


Can you please help me on the below?

I have data starts from Column B
everyday one or the other people will open the file and make changes on the data.
I would like to track all the changes made in a row is captured in column A like below

say if any changes is done in row 4 ( B4 is changed from 100 to 200 and
G4 is changed from Yes to No

as soon as these changes are happened,
in Cell A4 i should get like
Cell B4 - value $100 has been changed to $200 on 22-Oct-2010 and time by John and
Cell G4 - value Yes has been changed to No on 22-Oct-2010 and time by Jim

If 20 changes are done in day everything has to be caputured

Note: The workbook is not shared
and I have 2000 rows of data in a sheet.

thanks for your help..