Trying to figure out a solution for an age verification.

Alright, I'm trying to come up with a way to verify people's ages over 18 and above with a possible use of a credit card. I've been looking at a few scripts, they may be close but it isn't what I'm looking for.
As of right now, I have a group for people to join, but they must provide an identification card (somewhat efficient, but I want to improve the efficiency). For the reason of doing this is we currently support people 15 + 17 (High School Student Ages) and also people who are over 18 My dating forum doesn't support adult content such as pornography and anything within that subject (following the rules of forum motion).

<a href="Example.com">Verify Age</a>     <a href="Example.com">Don't Verify Age</a>

I'd like to be able to somehow form a stronger way to secure this involving email notification and credit. I'm even willing to go out and try Javascript if I have to. I'm trying to make keep out the pedos from dating the younger teens and so forth. Any ideas or suggestions?

No one will add their credit card information to prove they are above 18 to join a forum.

People verify there credit cards all over the internet.
There must be a credit card verification site somewhere which gives you like an embed code or something.