Declare Function
Code:
Private Declare Function SendMessage Lib \"user32\" Alias \"SendMessageA\" _
(ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) _
As Long
Const WM_SYSCOMMAND = &H112
Const SC_MONITORPOWER = &HF170
turn off

Code:
SendMessage Me.hwnd, WM_SYSCOMMAND, SC_MONITORPOWER, 2&
turn on

Code:
SendMessage Me.hwnd, WM_SYSCOMMAND, SC_MONITORPOWER, -1&