Sub Domain Issue

[is300]

I need to block google from reading product pages on a sub domain. Can I use my main domain's robots.txt file to do this?

subdomain.domin.com/shop/detail/20414/

If yes, would my robots.txt read:

User-agent: googlebot
Disallow: subdomain.domain.com/shop/detail/

[encyclo]

No, each subdomain must have its own robots.txt - the one on the main domain has no effect over any subdomains at all.