You may be able to do that "dirtily" with a form action, which loads on their site, or maybe within a frame on your site. It just depends if they would support that kind of thing, and if you had...

Hello Jonas, I visited your site and your footer appeared to be the same width as the rest of your page, and it looked fine. As for the header, could I recommend a header with a red background and...

Which operating system are you using (Windows, Linux [which distribution?], Mac, etc.)? Also, from experience, I would advise against using FireFTP for anything more than extremely light duty...