This sounds like a good scenario for a custom form solution. The catch is that there is no way to to distinguish between the user adding information to the body of the task and the user adding the specific information you're looking for. If there are common reasons, you could consider setting up a combo box on a custom form page to capture them.

If you go with a script to handle the validation, you'll need to update each user's machine to make the change described at http://www.outlookcode.com/d/secforms.htm in the section on Forms in Other Users' Mailboxes.

It probably can be done
--
Sue Mosher, Outlook MVP
Author of Configuring Microsoft Outlook 2003
http://www.turtleflock.com/olconfig/index.htm
and Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers
http://www.outlookcode.com/jumpstart.aspx

"Jerod Mills" wrote in message ...
Our users share tasks in a shared mailbox. Group leaders set these tasks up
and users work on them and close them. Group leaders want it automated for
them to HAVE to add detail as to why the task was not completed on time.


"Sue Mosher [MVP-Outlook]" wrote in message
...
We need some context here. Is part of a custom task form? An Outlook add-in?
Some other type of application?

"Jerod Mills" wrote in message
...
I need to restrict a user from closing out of a task if the completed date
is later than the due date without putting something in the description.
I
have tried to look at macro's but couldn't find anything valuable there.
Any help would be greatly appreciated