> How would you denie access to a certain module if someone else is working with it ? I guess you don't do this (mainly because it is not easy to do).

Walter,

Actually two reasons, the one you mentioned and the fact that in a web envioronment you get a much larger number of folks who simply leave your app rather than follow some procedure for leaving.

For example, a web app must address the admin user who naviagtes to an edit page for a user's information (which I would normallyprevnet anyone else from getting edit roghts tpo that user's record) and then simply jump away to Google.com to go off on another adventure. Because of this possible and also likly scenario I don't deal with any contention issues until the system receives a submittal. Then, after submittal, the system deals with whether or not the system is in a state that can accpet what has been submitted.