procedure TDemo_Form.Button1Click(Sender: TObject);
begin
  CallForm(TForm1);
end;

procedure TDemo_Form.Button2Click(Sender: TObject);
begin
  CallForm(TForm2);
end;

procedure TDemo_Form.Button3Click(Sender: TObject);
begin
with TcxPageControlAccess(PC) do
    if DoCanClose then
      DoClose;
end;


procedure TDemo_Form.CallForm(aForm: TFormClass);
var
  newTabClass: TFormClass;
  TabSheet: TcxTabSheet;
begin
  newTabClass := aForm;
  if Assigned(newTabClass) then
  begin
    TabSheet := TcxTabSheet.Create(PC);
    TabSheet.PageControl := PC;
    PCForm := newTabClass.Create(self);
    PCForm.BorderStyle := bsNone;
    PCForm.Parent := TabSheet;
    PCForm.Align := alClient;
    PCForm.Show;
    tabSheet.Caption := PCForm.Caption;
    tabSheet.Name := PCForm.Name;
    PC.ActivePageIndex := PC.PageCount - 1;
    Panel2.Caption := tabSheet.name;
  end;
end;