Ajax? Help (Not sure if is Ajax)

[MDowner]

On 123-reg, when you go to purchase a domain, you are given the option of using your stored payment type, or using a new credit card.

There is a checkbox that allows you to choose which you want.

On clicking of this checkbox, the box below changes from stored type, to contain a credit card information input form.

I want to have this functionality, but don't know what to search for. And the things I have searched for seem to not be in anyway related.

All help appreciated!

Martin

[Dave]

That's probab;y just a show/hide toggler (javascript).  Search for "select onchange toggle div" or something like that.