Simple PHP Includes

I can’t beleive I’m actually having trouble with this. I’ve done it a million times, and this simple code is giving me difficulty.

<?php include(“menu.php”); ?>

Doesn’t work. I have the menu.php in the right folder, nothing is misspelt, I’ve done this so many times. Yet when I check the source code from the webpage, the php I’ve written above comes up in pink writing in the source code as if it’s just normal HTML. All this code is doing for me is pretty much leaving a blank space where it is supposed to include.

Anyone know whats going on?