<?php

include 'include_fns.php';
if ($id = store_new_post($_POST)) {
    include 'index.php';
} else {
    $error = true;
    include 'new_post.php';
}
<?php

include 'include_fns.php';
if ($id = store_new_post($HTTP_POST_VARS)) {
    include 'index.php';
} else {
    $error = true;
    include 'new_post.php';
}