[Samba] How to hide shares for users that have no rights

[Vempati Srinivasa Rao]

Good morning.
I am using samba 3.0 on RedHat Linux 9.0  and Linux machine is having lot of
users and groups . I am trying to solve a problem. 
I have created, for example, 10 shares ( each share is having different
valid users and groups ) and I can access only 4 of them (I have rights to
read or write only for 4 shares). Well, is it possible to hide to my
browsing the 6 shares that I can not access. 
Thank you very much 
Srinivasa Vempati

My Partial Configuration File looks like this:

#This config file contains all samba shares
[share1]
	path=/usr/dir1
	comment=Nas Share dir1
	valid users = user1, user3, user6
[share2]
	path=/usr/dir2
	comment=Nas Share dir2
	valid users = user2, user4, user6

If I try to access using user1, now i'm seeing all shares on client machine.
because of share2 is not having access permissions to user1, this share
should not be visible. 
Can anybody help to solve this