There is also something wrong with the site code...
<?php include('form.php'); ?>
is showing up which indicates that PHP is not being parsed as it shouldn't show up in the HTML like that...
Then you have
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
which is out of date, you need
You need to change your index.html in to index.php so that your PHP is parsed or you need to tell the PHP to parse all .htm, .html files for PHP, much simpler to rename the index page extension to .php