Javascript + Formmail small job

1) Take the formmail script, which mails information from a form. When the submit button is hit, it goes to a default "thank you" page with the information that was submitted. I want that page to match the rest of my site (a simple design, a background color and table). I also want to be able to add HTML, a download link, text and a few other things on my own. 2) A javascript that will take the answer from the 1st form box, multiply it by 0.01 and then multiply it by the specified second form box. When the Calculate button is clicked, the answer will appear in the results box.