sample stack programm

Hallo!

I?m trying to translate a borland pascal sample program to gpcp.
The lines "Sys.Console.WriteLine(myEnumerator.Current);" and
"Sys.Console.WriteLine(myStack.Count);" does not compile. Why does it 
not compile?
The delphi sample programm is here 
http://delphi.about.com/library/fcl/system/collections/blfclstack.htm

Kind regards
Helmut

MODULE SamplesStack;
IM****T Col := mscorlib_System_Collections, Sys := mscorlib_System, CPmain;

VAR myStack : Col.Stack;

PROCEDURE PrintValues(myCollection: Col.IEnumerable);
VAR myEnumerator: Col.IEnumerator;
BEGIN
   myEnumerator := myCollection.GetEnumerator;
   WHILE myEnumerator.MoveNext DO
     Sys.Console.WriteLine(myEnumerator.Current);
   END;
   Sys.Console.WriteLine;
END PrintValues;

BEGIN
   NEW(myStack );
   myStack .Push("Hallo");
   Sys.Console.WriteLine(myStack);
   Sys.Console.WriteLine(myStack.Count);
   PrintValues(myStack);
END SamplesStack.