You could use my Multi-Thread UDF this way : #include <Constants.au3> #include <WindowsConstants.au3> #include <MsgBoxConstants.au3> #include <GUIConstants.au3> #include "..\Files\PMT-UDF.au3" Opt("MustDeclareVars", True) Global $GUI_HWNDPARENT Global $GUI_HWNDPARENT_Width = 786 Global $GUI_HWNDPARENT_Height = 502 Global $GUI_HWNDPARENT_Event_Message Global $BTN_Close Global $BTN_Maximize Global $B