#include 
     
       $mainwindow = GUICreate("Hello World", 300, 200)GUICtrlCreateLabel("Hello world!", 30, 10)$okbutton = GUICtrlCreateButton("opened the subform", 20, 30, 150) 主窗口点击按钮后又创建了一个新的子窗口，在关闭子窗口时主窗口也关闭了 $dummywindow = GUICreate("Dummy window for testing ", 200, 100) GUISwitch($mainwindow)GUISetState(@SW_SHOW) While 1  $msg = GUIGetMsg(1)   Select    Case $msg[0] = $okbutton      GUISetState(@SW_SHOW,$dummywindow)     Case $msg[0] = $GUI_EVENT_CLOSE And $msg[1] = $mainwindow        Exit  Case $msg[0] = $GUI_EVENT_CLOSE And $msg[1] = $dummywindow          GUISetState(@SW_HIDE,$dummywindow)  EndSelectWEnd