Turn a monitor off

[Simon Canning]

Here is my code:

    Public Declare Function PostMessage Lib "user32.dll" _
Alias "PostMessageA" _
(ByVal hwnd As IntPtr, _
ByVal wMsg As Int32, _
ByVal wParam As Int32, _
ByVal lParam As Int32) As Int32

    Public Const WM_SYSCOMMAND = &H112&
    Public Const SC_MONITORPOWER = &HF170&

And here is the actual code to do the task:

PostMessage(Me.Handle, WM_SYSCOMMAND, SC_MONITORPOWER, 2&)

This puts the monitor into standby. Can I please have some help to modify the code to turn the monitor off, and also the code to turn it back on.

Thanks