If I have the domain domain.com

I have a reseller account and a couple friends looking to host small sites. They want theirname.domain.com

Can I create them their own FTP login that only has access to their subdomain, so they cant mess around with domain.com?

If so, how?
Thanks :D

Yes, create sub-domain. And make FTP username the sub-domain.

HTH

o ok cool thanks :)