Stop Users Messaging In Same User Group?

Hi all, I have two user groups, Registered and Authors.
How can I stop Authors messaging other users in the Author group?
Thanks in advanced

I'm pretty sure this could be done with a few changes to uddeIM's php code.

But then, why on earth would someone want a feature like this?
This souns very odd to me.

Appologies, I didn't realise a reply had been given! I need to do this as the Authors have no need to message other Authors. There's two groups simply for a distinction between two users, one has certain features, and the other has chose to have others...

Would you know what php I could use, as my php skills aren't soo good yet!

Thanks

Post edited by: ampz21, at: 2010/08/11 23:35

Anyone? This feature is really important for me, any help? :dry: