Code To parse FB url and Twitter username

facebook-url-parse.php

<?
protected function valid_facebook_url($field){
    if(!preg_match('/^(http\:\/\/|https\:\/\/)?(?:www\.)?facebook\.com\/(?:(?:\w\.)*#!\/)?(?:pages\/)?(?:[\w\-\.]*\/)*([\w\-\.]*)/', $field)){
        return false;
    }
    return true;
}

twitter-username-parse.php

<?
protected function valid_twitter_username($field){
    if(!preg_match('/^(\@)?[A-Za-z0-9_]+$/', $field)){
        return false;
    }
    return true;
}