function alphanumericAndSpace( $string )
    {
        return preg_replace('/[^a-zA-Z0-9\s]/', '', $string);
    }

function cp_filter($text) {
    $text = strip_tags($text);
    $text = trim($text);
    $char_limit = 5000;
    if( strlen( $text ) > $char_limit ) {
        $text = substr( $text, 0, $char_limit );
    }
    return $text;
}

function cp_check_email($email) {
    if (!ereg("^[^@]{1,64}@[^@]{1,255}$", $email)) {
        return false;
    }
    $email_array = explode("@", $email);
    $local_array = explode(".", $email_array[0]);
    for ($i = 0; $i < sizeof($local_array); $i++) {
        if (!ereg("^(([A-Za-z0-9!#$%&'*+/=?^_`{|}~-][A-Za-z0-9!#$%&'*+/=?^_`{|}~\.-]{0,63})|(\"[^(\\|\")]{0,62}\"))$", $local_array[$i])) {
            return false;
        }
    }
    if (!ereg("^\[?[0-9\.]+\]?$", $email_array[1])) {
        $domain_array = explode(".", $email_array[1]);
        if (sizeof($domain_array) < 2) {
            return false;
        }
        for ($i = 0; $i < sizeof($domain_array); $i++) {
            if (!ereg("^(([A-Za-z0-9][A-Za-z0-9-]{0,61}[A-Za-z0-9])|([A-Za-z0-9]+))$", $domain_array[$i])) {
                return false;
            }
        }
    }
    return true;
}