[Samba] Getting Samba to ask for Username and Password

[AndyLiebman at aol.com]

Can somebody tell me how to get samba to ask me for a username and password 
when I click on my Samba server in Windows XP Explorer? 

When I click on another computer on the network (Workstation A) from a 
workstation (Workstation B) where I'm NOT logged in with a username:password that 
Workstation A recognizes as having an account, I get a dialog box asking me for 
a username and password. 

But when I click on the Samba server from a machine that doesn't have an 
account on the Samba server, I just get a message saying "the resource can't be 
found or I don't have permission to use it. Contact my administrator." Or 
something like that. 

How do I have to configure smb.conf to get the username:password dialog box? 

Regards,
Andy Liebman