I picked up some code online but I seem to have missed something:
I created a file called logout.php which I placed in the main folder
//*****session_destroy() will destroy the session
and in the index.html I added
<A HREF = Pinto/logout.php>Log out</A><A HREF = index.html</A>
which I know is wrong! I just want to press the button, destry and return to the main page.