URL не видит русский. Что делать?

if ( ! function_exists('url_title'))
{
    function url_title($str, $separator = '-', $lowercase = FALSE)
    {
        if ($separator == 'dash')
        {
            $separator = '-';
        }
        else if ($separator == 'underscore')
        {
            $separator = '_';
        }

        $q_separator = preg_quote($separator);

        $trans = array(
            '&.+?;'                 => '',
            '^[а-яА-ЯёЁa-zA-Z0-9]+$]'    => '',
            '\s+'                   => $separator,
            '('.$q_separator.')+'   => $separator
        );

        $str = strip_tags($str);

        foreach ($trans as $key => $val)
        {
            $str = preg_replace("#".$key."#i", $val, $str);
        }

        if ($lowercase === TRUE)
        {
            $str = strtolower($str);
        }

        return trim($str, $separator);
    }
}