[vb.net 2003] problem on turning off the monitor

hey there!
im trying to turn off my monitor using api, lots of vb6 examples found here.
i tried to convert it to vb.NET, but it doesnt seem to work.
please check it out and tell me if u got a clue :D

VB Code:

Private Declare Function SendMessage Lib "user32.dll" Alias "SendMessageA" _
(ByVal hwnd As Int32, ByVal wMsg As Int32, ByVal wParam As Int32, ByVal lParam As Int32) As Int32
'
 
    Public Sub turnoffmonitor()
        Const HWND_BROADCAST As Int32 = &HFFFFI
        Const WM_SYSCOMMAND As Int32 = &H112
        Const SC_MONITORPOWER As Int32 = &HF170
 
        SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, 0&)
    End Sub

and yes, i DO know i am not good at translating vb6 to vb.net :p