procedure CreateChildFrm(AForm:TCustomForm;const AFormClass:TFormClass);
function isExist():boolean;
var
  i:integer;
begin
  result:=False;
  for i :=0 to Screen.FormCount-1 do
  begin
    if Screen.Forms[i].ClassType=AFormClass then
    begin
      Result:=True;
      AForm:=TForm(Screen.Forms[i]);
      Break;
    end;
  end;
end;

begin
  if not isExist() then
  begin
    AForm:=AFormClass.Create(Main);
    Winapi.Windows.SetParent(AForm.Handle,Main.Panel2.Handle);
  end else
  begin
    ShowWindow(AForm.Handle,SW_MAXIMIZE);
    AForm.BringToFront;
  end;
   AForm.Show;
end;