Hi Friends

I'm working for a site whose business is Domain Registration and they put Individual pages for Each TLD's(.com, .in etc) now i planned to change the page name with keywords

For example

For .com TLD Page i planned to change the page name as .com_domain_Registration

.com_domain_Registration or Com_domain_registration

From the above two names which one is best
is there any problem in dots in page name?