I have a html-page (contact.html) and i want to put on that page a contact form (index.php).
I have tried two things.

1) include in contact.html:
<?php include("index.php"); ?>
--> no result, blank page

2) copy the code from index.php in contact.html:
<?php
/*
php code from index.php
*/
?>
--> the code is shown and not the contact form

What is the problem? When I open index.php directly in the browser there is no problem.