#include <GUIConstantsEx.au3>
#include <ButtonConstants.au3>
$hGUI = GUICreate('GUI', 200, 200)
$Button_1 = GUICtrlCreateButton('Две' & @LF & 'строки', 50, 80, 100, 40, BitOR($GUI_SS_DEFAULT_BUTTON, $BS_MULTILINE))
GUISetState()
While 1
Switch GUIGetMsg()
Case $GUI_EVENT_CLOSE
Exit
EndSwitch
WEnd