$GUI=GUICreate('------',500,500)
$Button=GuiCtrlCreateButton('надпись',100,100,200)
GUISetState()
sleep(5000)
GuiCtrlSetData($Button,'новая надпись')
sleep(5000)
GuiCtrlSetData($Button,'старая надпись')
sleep(5000)
GuiCtrlSetData($Button,'надпись')
sleep(5000)