Class Question

Hello, This is the first time I write OOP in PHP. I wrote a small class for Mysql and from the index.php, I am calling the new function. I have a display before new class and I have a display after the new and only the display I am getting is the before class and after that there is no error. Is there any thing I should know before using the class? I have the class in a protected directory and index.php in the main directory. <html> <body> <?php include("incs/Mysql_db.inc"); $db = new Mysql_db(); if($db.return_code) {

      echo " Connection is made";

} else {

      echo "Couldn't make the connection";

} ?> </body> </html> and the class is <?php class Mysql_db { var $host; var $db_name; var $uid; var $pwd; var $link; var $query; var $result; var $return_code; var $error_info; var $row; var $number_of_columns; var $number_of_rows; function Mysql_db() {

      $this->host = hostname;
      $this->db_name = dbname;
      $this->uid = uid;
      $this->pwd = pwd;
           $link = @mysql_db_connect($host, $uid, $pwd);
       }    

//*********************************** run the query *************************** function run($query) {

      $this->number_of_columns = 0;
      $this->number_of_rows = 0;
      $this->return_code = 0;
      $this->error_info = "";
           $this->result = @mysql_db_query($db_name, $query, $link);
      if(!$result)
      {
          echo "Query didn't run";
          echo @mysql_error();
          $error_info = @mysql_error();
      }
      else
      {
          $number_of_columns = @mysql_num_fields($result);
          $number_of_rows = @mysql_num_rows($result);
          $error_info = "";
      }//end of bad return code
      return $return_code;

}// end of run query function //********************************* extract or fetch a row ********************** function get_values() {

      $this->row = @mysql_fetch_object($result);
      if($row)
      {
          extract($row);
          $return_code = 0;
      }
      else
      {
          $return_code = -1;
      }// end of if

}//end of get_values function }//end of class ?>