Disable ability for the user to link to a node

GoDiagram (6 and previous)
1

I have a requirement to disable ability for the user to link to a node.

The node is a GoTextNode
All links need to be created in code(This part is fine).
I would like to know how to disable the user from creating links.
Any code samples is appreciated.
2

http://www.nwoods.com/forum/forum_posts.asp?TID=295