CoreData and Binding question

FROM : Tony S. Wu
DATE : Fri Apr 06 19:36:14 2007

i have 2 entities with one-to-many relationship between them, and 2 
table views setup accordingly.

Entity A <---->> Entity B

in entity A, one of the property is the sort descriptor, determining 
how entity B should be sorted in the table view.
my problem is, i would like to prevent the sort descriptor property 
from being changed if multiple entity A are selected.
because when i have multiple entity A selected, and i change the sort 
descriptor from the table view, all the selected entity A's sort 
descriptor properties are changed.
thanks for any suggestion.

Tony S. Wu
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