ward2000, But it is not that difficult to do if you have read and understood the tutorial:
#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>
$hGUI = GUICreate("Test", 500, 500)
$hTab_0 = GUICtrlCreateTab(10, 10, 480, 480)
$hTab_00 = GUICtrlCreateTabItem("00")
$hTab_01 = GUICtrlCreateTabItem("01")
GUICtrlCreateTabItem("")
GUISetState()
$hTab_Win1 = GUICreate("", 200, 300, 20, 100, $WS_POPUP, $WS_EX_MDICHILD, $hGUI)
$hTab_1 = GUICtrlCreateTab(0, 0, 200, 300)
$hTab_10 = GUICtrlCreateTabItem("10")
$hTab_11 = GUICtrlCreateTabItem("11")
GUICtrlCreateTabItem("")
GUISetState()
While 1
Switch GUIGetMsg()
Case $GUI_EVENT_CLOSE
Exit
Case $hTab_0
Switch GUICtrlRead($hTab_0)
Case 0
GUISetState(@SW_SHOW, $hTab_Win1)
Case 1
GUISetState(@SW_HIDE, $hTab_Win1)
EndSwitch
EndSwitch
WEnd
All good? M23