Make a log table with user,transacts...etc.
-When addition is occured and user saves - Add a record to
that table including name,id etc of that user.
-When user modifies - copy original record to file x.
when user saves copy modified record to y.
compare fields if any field does not matches, add that
field to a string and append that to log table by saying
field a,b,c changed on xx date, by zz user etc.
-When delete occurs simply add 'deleted by zz user on xx
date
Bada