<?php
    function community_name_valid($_name)
    {
        if (!$_name)
        {
            return 'You must give your community a name.';
        }
        if (strlen($_name) < COMMUNITY_NAME_MIN)
        {
            return 'Your community\'s name must be at least ' . COMMUNITY_NAME_MIN . ' characters long.';
        }
        if (strlen($_name) > COMMUNITY_NAME_MAX)
        {
            return 'Your community\'s name must be at most ' . COMMUNITY_NAME_MAX . ' characters long.';        
        }
        if (!preg_match('/^[A-z0-9][\w\-\.\_ ]+$/', $_name))
        {
            return 'Your community\'s name cannot have non alpha-numeric characters. (hyphens (-), underscores (_) and periods (.) are allowed)';
        }
        return null;
    }
?>