oo programing help needed?

[shoko2004@hotmail.com (shoko)]

i have the following:
------------------------------------------
package one is
  type one  is tagged private; 
  type one_ptr is access all one'class;
  
   procedure set_name(name:String;this:in out one);
  function  get_name(this:one) return string;
  
  private
     type one  is tagged 
     record
         name:String(1..256);
     end record;
  
   
end one ;
---------------------------------------------
with one;

package two is
   type two is new one.one with private ;
   private
      type two is new one.one with null record;
end two;
---------------------------------------------
with two;

package three is
   type three is new two.two with private ;
   function  get_name(this:three)  return string;
   private
      type three is new two.two with null record;
end two;      

-------------------------------------------
package body three is
   function get_name(this:three) return string
     s:string(1..10);
   begin
     return s+ this.name;  <-- no selector "name" for type three
  end get_name;

end three;


i get no selector "name" for type three

how to solve this problem??????