Hi! I�m developing a simple linked list to hold different data types.. I have to one superclass , with two derived classes.. I have declared a 'Class type which I use to access all of my structures, I have no trouble adding data to the list. The error occures when I wan't to extract the data and Print it to the screen.. look at the following code example: program.ads: type T�cken is tagged null record; type Siffra is new Tecken with Record Element : Integer; end record; procedure Print(S : Siffra); type Bokstav is new T�cken with record Element : Character; end record; procedure Print(B : Bokstav); type pTecken is access all Tecken'Class; program.adb -- I have to simple procedures which Print the values of Class bokstav, '' notice .. pekare is of type pTecken .. procedure Print(B : Bokstav) is begin Put(B.Element); end Print; procedure Print(S : Siffra) is package Iio is new Integer_Io(Integer); use Iio; begin put(S.Element); end Print; -- Then I have this procedure to extract the elements from the list. Pekare is Pocedure Display is begin while Lista /= null loop Print(Lista.Pekare); Lista := Lista.Next; end loop; end Display; Really need help on this one thx Mattias