public function utf8_str_split($str) {
        // place each character of the string into and array
        $split=1;
        $array = array();
        for ( $i=0; $i < strlen( $str ); ){
          $value = ord($str[$i]);
          if($value > 127){
            if($value >= 192 && $value <= 223)
              $split=2;
            elseif($value >= 224 && $value <= 239)
              $split=3;
            elseif($value >= 240 && $value <= 247)
              $split=4;
          }else{
            $split=1;
          }
            $key = NULL;
          for ( $j = 0; $j < $split; $j++, $i++ ) {
            $key .= $str[$i];
          }
          array_push( $array, $key );
        }
        return $array;
      }

    public function clearstr($str){
        $sru = 'ёйцукенгшщзхъфывапролджэячсмитьбю';
        $s1 = array_merge($this->utf8_str_split($sru), $this->utf8_str_split(strtoupper($sru)), range('A', 'Z'), range('a','z'), range('0', '9'), array('&','«','»',' ','#',';','%','?',':','(',')','-','_','=','+','[',']',',','.','/','\\'));
        $codes = array();
        for ($i=0; $i<count($s1); $i++){
                $codes[] = ord($s1[$i]);
        }
        $str_s = $this->utf8_str_split($str);
        for ($i=0; $i<count($str_s); $i++){
                if (!in_array(ord($str_s[$i]), $codes)){
                        $str = str_replace($str_s[$i], '', $str);
                }
        }
        return $str;
    }