I need to submit 3 forms triggered by just one submit button.

On my humorlab.com site I have a "tell a friend" button on each page. This opens a page where my visitors can enter in their email and that of their friends - then press submit and have an emial sent to each of their friends about that particular page.

I would like to add 2 checkboxes to my form - one will subscribe the visitor to a netezines.com humor newsletter - the other to subscribe them to my own site news letter.

How can this be done off a single form???