problem in changing Discriminants from access type

["Gil Kaspi" <kaspi@ibm.net>]

this program was build to simulate dynamic array .
(it should be a package that has
    type arr is private;   and    arr defenition is access to arr_node)
----------------------------------------------------------------------------
-----------------

procedure d_array is

 type Arr_Node;

type arr is access arr_node;

type Test is array (Integer range <>) of Integer;

subtype Int_Limits is Integer range -1000..1000;

type Int_Arr is array (Int_Limits range <>) of Integer;

type Arr_Node (Start : Int_Limits :=1; Ends : Int_Limits := 0) is
record
   Store : Int_Arr (Start..Ends);
end record;

-- declare --
D_Arr : Arr;

begin

-- create --
D_Arr := new Arr_Node'(Start => 1, Ends => 0, Store => (others => 0));

-- change --
D_Arr.all :=(Ends => Index, Start => Index , Store => (others =>1));

end;
----------------------------------------------------------------------------
------------------------

!!! first, writing this code without the access will work OK.
running this code will raise CONSTRAINT_ERROR.
the problem I think is hiding in the last line

10x 4 any1 that will help
gil.