Interactive JavaScript Form - looking for this script

Hiya all.

Im trying to create a search form for a simple estate agent site, I managed to set up a simple form for a basic search when someone is looking to buy a property, but what I would ideally want to be able to do is have 2 radio buttons on the top with the "buying" selected by default, but if someone clicks the "renting" radio button the rest of the form fields changes and also the target of the form will be sent to the search_renting_page instead of the search_buying_page .

I know if i simply have a button/link there tat takes them to the renting page for search is much easier, but its not what I want to achieve.

So I was hoping if anyone have come across a script that does this or can point me to the right direction to get this done. please note I have no knowledge of javascript.

Many Thanks