Frontend Duplicate form Elements

Hi Guys,

Basically the current form consists of 3 fieldsets, one for general info, one with details of the request and one with the contact info.
I want my visitors to be able to click a + button beneath the fieldset for the request details and so copy all those input fields, so they only have to fill in the other info once. Is this something that has been incorporated in a contact form plugin, currently i’m using cforms II but that doesnt have the option. Or is it something I can do with all plugins, just with some jQuery. If so is there anyone out there that could help me on the way…point me to proper plugins or tutorials….

your help is much appreciated.