I'm runnning a smb share on a ubuntu server. This is my current /etc/samba/smb.conf file:

[Media]
    comment = Media
    path = /media/Media
    read only = no
    browsable = yes


I would like users to access the share without entering a password but read-only. Only users which have a account with a password should be able to write. How can I do that the easiest?