group access

[Jianping Zhu]

I have a directoy "book"  shared by a group of user wiht rw access. When a
groupuser1 create a directoy in linux system by using "mkdir test"
after "ls -al"
I got following msg:

drwxrwsr-x    2 groupuser1   book         4096 Mar 18 16:41 test
every thing is fine by now.
But when groupuser1 ftp dirctoy "testftp" to "book" after "ls -al"

i got 

drwxr-sr-x    2 groupuser1   book         4096 Mar 18 16:46 testftp

other group member will not have write access to "testftp"
I have smba, when groupuser1 create a directoy "testwin" from window
the sametime happens

drwxr-sr-x    2 groupuser1   book         4096 Mar 18 16:46 testwin

other group member will not have write access to "testwin"

How can i fix this problem to have testftp and testwin to have group
write access when group member creates them?

Thank.