looks good erwin...

a little tip, when variable values are involved like that? try always to add them into global.php.
so your $allowurl should be identified to something like that:
Code:
// allow url's after xx posts
$allowurl = 15;
will be alot easier to be changed onto one file, then to look through several ones, in case the user tries to change the value after... that will make it easier on newcommers to find something in php files.
let me know what you think.