In that case, you simply need to change the MessageClass on the existing items to point to your new form's class, e.g. IPM.Contact.FormB. See http://www.outlookcode.com/d/newdefaultform.htm#convert for several tools and scripts to accomplish this.

Make sure that the form definition for FormB includes the custom property, visible on the User-defined Fields in This Item list on the All Fields page.


--
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

wrote in message oups.com...
Sorry, I will try to be more clear. We have two custom forms, form A
and B. One is no longer used and we want to convert all of the contacts
using form A to form B so that every contact is using the same form.
There is a custom field in both forms that we want to make sure the
data is brought across to these contacts when they are converted from A
to B.

Thanks.