HTML form not directing to index.php on submit

Ah, the problem was the logout button.

<?php include $_SERVER['DOCUMENT_ROOT'] . '/artgibney/includes/logout.inc.html.php'; ?>

which is actually a form,

<form action="" method="post">
  <div>
    <input type="hidden" name="action" value="logout">
    <input type="hidden" name="goto" value="/artgibney/admin/">
    <input type="submit" value="Log out">
  </div>
</form>

I have moved this line and it is working now.

Thanks for your patience with me.
Shane
PS The html you posted is no problem.