[dba-SQLServer] Why is my view not editable?

I create a view of parent / child, joined on FK etc.  Filter to one specific parent using the 
parent's PKID.  I then try to edit a field in the child and it doesn't do anything, IOW it is locked 
for some reason.  I thought that simple views like this are supposed to be editable.

-- 
John W. Colby
www.ColbyConsulting.com