User-Agent: *
Disallow: /

User-Agent: Googlebot
Disallow: /*.png
Disallow: /*.rb
Disallow:

User-Agent: Slurp
Disallow: /*.png
Disallow: /*.rb
Disallow:

User-Agent: msnbot
Disallow: /*.png
Disallow: /*.rb
Disallow: