please help my cvs!

[l-cong]

sir:

    my cvs server happened to a question.

    after a import mypro,the user who is one of the cvs group can not checkout mypro.the user is login in his username ,a normal user.

    the question is

"address@hidden guo]$ cvs checkout yang
cvs [checkout aborted]: /home/david/cvs/CVSROOT: Permission denied"

   please help me ,

thanks