Hello Sean

What i mean to say that user have maximum right to perform addition/deletion/substitution.Assuming I/you have all access and now request came to add/delete/substitute user in current hierarchy showing.

a) Deletion/substitution process

Deleting a single node in the middle of the tree then fill up the existing user into the vacancies as created.

b) Addition/updating Process

Add the user in middle/anywhere of node of the tree.Updates to the nodes are performed by searching for the key of each node.if user exist then do not insert else insert the user.We have to consider the level when we are adding /updating user(using userid).

Let me know if you need any more information

Thanks again for your help

R