Age verification page similar to what is used on sites promoting alcohol

I am looking for an Age verification page similar to what is used on sites promoting alcohol (i have attached a couple of screen shots to give you an idea of what i require. The form has to have a country dropdown and depending on which country is selected will determine the minimum age of drinking in the country and validate this against the date of birth supplied. The page/script also has to have a redirect that all site pages are sent to the age verification page until authenticated.