Set write permissions by default for group?

[David Miller]

I'm setting up a share through Samba and want one of the folders  
under the share to set the group and give write permissions to that  
group for any file/folder created. Is their a method to make files  
and folders inherit the permissions and group from it's parent  
directory? Right now all new files and folders are created with the  
correct group but do not get write permissions for that group.