Contact Form Plugin recomendation

Hi – I’m looking for a Contact form plugin that will allow different content to be shown depending on a drop down selection.

The form will have common standard content:Name, Phone, Email.

I want it to show different questions from there, from a drop down box if they select “Birthday” it will then show a group of further options for the birthday person. If they select “School” it will not show the birthday options but some additional options specifically for schools.

Hopefully that’s clear enough. Anyone got any recomendations?

Cheers, Scott.