I have assigned HeaderName path/.../head.html in .htaccess,in which my php page (as it is set in action tag in a form at head.html) is sending output from html to another page (that's obvious), and to display output on the same page, I must build my php code with html on the same page, and save it as .php extension, but HeaderName in .htaccess is not accepting .php extension, also I am strictly not allowed to use superglobal variables (like SESSION) !! please help,,
This is how you use .php fine in HeaderName directive:
AddType text/html .php
Addhandler application/x-httpd-php .php
HeaderName /includes/header.php