#Include <WindowsConstants.au3>
$hForm = GUICreate('MyGUI', 400, 400)
$hTab = GUICreate('', 300, 300, 50, 50, BitOR($WS_CHILD, $WS_TABSTOP), -1, $hForm)
$Tab2 = GUICtrlCreateTab(0, 0, 300, 300)
GUICtrlCreateTabItem('Item3')
GUICtrlCreateTabItem('Item4')
GUICtrlCreateTabItem('')
GUISwitch($hForm)
$Tab1 = GUICtrlCreateTab(10, 10, 380, 380)
GUICtrlCreateTabItem('Item1')
GUICtrlCreateTabItem('Item2')
GUICtrlCreateTabItem('')
GUISetState(@SW_SHOW, $hForm)
GUISetState(@SW_SHOW, $hTab)
While 1
Switch GUIGetMsg()
Case -3
Exit
Case $Tab1
Switch GUICtrlRead($Tab1)
Case 0
GUISetState(@SW_SHOW, $hTab)
Case 1
GUISetState(@SW_HIDE, $hTab)
EndSwitch
EndSwitch
WEnd