CommitInfo - how do I figure out branch or Trunk..

[Vivek Venugopalan]

Hello
  I would like to figure out whether a commit request is happening on a
branch or the trunk.  Is there any way to do that in a commitinfo triggered
script?  The background is that I want to prevent check in of files to
branches which is considered as "dead" from the project perspective.  Any
ideas?

Thanks
Vivek