Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal _
  hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) _
  As Long
Private Const WM_SYSCOMMAND = &H112&
Private Const SC_MONITORPOWER = &HF170&
 
SendMessage Me.hWnd, WM_SYSCOMMAND, SC_MONITORPOWER, 1&