Restrict commands available in an SFTP session

[Sonja Meyer]

Hello,

i am using SFTP with CHROOT. I want to allow my users that they can upload 

and download with the sftp server, but they should never do an MKDIR!
Is it possible to restrict commands and how can i do this?
i only found material of modifing the source...and that is not the best way for 

me.

regards 

Sonja Meyer
sonne_meyer at yahoo.de