Instead of writing something like this: Global $MainMSG ; Global massage for use on any gui function Func MainGUI() $MainGUI = GUICreate('Main') $SettingsGUI = SettingsGUI_Create($MainGUI) ; Create child windo inside the main GUI SettingsGUI_DrawSettings() $OtherGUI = OtherGUI_Create($MainGUI) ; Create child windo inside the main GUI $MainMSG = GUIGetMsg(1) While 1 SettingsGUI_MonitorChanges() ; If some