procedure TForm1.Button1Click(Sender: TObject);
var
  DataField: TStrings;
begin
  DataField := TStringList.Create; 
  DataField.Add(Format('%s=%s', ['Jonas', '15.03.1980'])); 
  ShowMessage(DataField.Values['Jonas']) 
  // will print the Birthday of Jonas 
  DataField.Free; 
end;