In order to parse HTML pages by PHP engine, you need to add the following line in the .htaccess file.
=> Clients using PHP 4.x should add the following link in .htaccess file
AddHandler application/x-httpd-php4 .htm .html
=> Clients using PHP 5.x should add the following link in .htaccess file
AddHandler application/x-httpd-php5 .htm .html
The .htaccess file is usually placed under ‘public_html’ directory of your account. If it is not there you can create one.