Log files

> Hello ...
> 
> I have a file that i want to trace all changes that are happening on that
> file. i.e. 
> *	date/time
> *	who has done the changes(username) and from which terminal (IP
> address)
> *	What are the changes
> 
> Now, what should i do to "create" the log messages? I tried to define in
> the syslog.conf file the filename(with its path) to be traced for changes,
> and define where to log the messages (i created a file in the /var/log
> directory); but i couldn't find any log message (while i've done the
> changes in the file to be traced) .
> 
> Any help is appreciated,
> 
> Thanks,
> Steven