Code:
#include <GUIConstants.au3>
$cxb = GUICreate("CXB", 164, 148, 413, 286)
$start = GUICtrlCreateButton("Start", 16, 56, 129, 33, 0)
$exit = GUICtrlCreateButton("Stop", 16, 96, 129, 33, 0)
GUISetState(@SW_SHOW)
While True
$MSG = GUIGetMsg()
Select
Case $MSG == $start
MsgBox(0,"start","")
Case $MSG == $exit
MsgBox(0,"Stop","")
EndSelect
WEnd