The first Verification Page (Cookie, Redirect) - How?

[datiswous]

You can look for a script on the internet and try to implement that. Or you can ask your question around that ("how can I implement this script in my site"). It's a lot less work to implement a script than make a new plugin.

http://stackoverflow.com/questions/15738...javascript
http://codecanyon.net/item/agelock-age-v...pt/4931493
http://jquerywall.com/demo-age-verificat...atepicker/
http://community.hostcheetah.com/thread/439

etc. etc. There are a lot of scripts on the net:

Google age validation script

Personally I find the Yes / No question better than asking to fill in a date.