I have a shared spreadsheet that is used by people on a call center.

In order to ensure none of the users, some of whom are not particularly
computer literate, don't save data over the top of each other I'd like to get
the sheet to save automatically after they enter the first cell of data- thus
removing the need to resolve conflicts, and more importantly them being
required to select the right course of action after a conflict comes up, or
else lose their data.

I am assuming it will be some form of macro, but don't know which commands
would be applicable.

I am using Excel in Office 2003 pro.