Looking for a Plugin or Hack: Ask for Commenter’s Age

Hi there! I went through the plugin directory and I searched under a lot of different topics and couldn’t find something that works quite this way– I would be super appreciative of help.

I would like to add a ticky box when someone comments asking them to affirm that they are over 13 in addition to asking them for their email address.

I found many plugins that ask for an age before viewing the full website, but we do not need that! All we need is an age verification when someone comments.

Thanks so much.