Execute command before sleep

[quadrplax]

I have a light bulb which I can turn on and off using UDP commands (I already have that working in AutoIt). What I would like to do is run a script before the computer goes to sleep to turn it off, and after it resumes to turn it on. I've already got the latter working, but not the former. I tried Task Scheduler with the kernel power log, but the command doesn't get executed until the computer resumes from sleep. I've tried some things using WM_POWERBROADCAST, but so far I haven't got that to work either. Here's what I've got so far:

Global Const $WM_POWERBROADCAST = 0x218

Global Const $PBT_APMSUSPEND = 0x4
Global Const $PBT_APMRESUMEAUTOMATIC = 0x12

While 1
    Sleep(100)
WEnd

GUICreate("Event Receiver")
GUIRegisterMsg($WM_POWERBROADCAST,"MY_WM_POWERBROADCAST")

Func MY_WM_POWERBROADCAST($hWnd, $uMsg, $wParam, $lParam)
   Switch $wParam
      Case $PBT_APMSUSPEND
         MsgBox(0,"PBT_APMSUSPEND","PBT_APMSUSPEND"&@HOUR&@MIN&@SEC)
      Case $PBT_APMRESUMEAUTOMATIC
         MsgBox(0,"PBT_APMSUSPEND","PBT_APMRESUMEAUTOMATIC"&@HOUR&@MIN&@SEC)
   EndSwitch
EndFunc

Does anyone know how to make this work?

Edited November 13, 2015 by quadrplax
Clarifying beginning

[JohnOne]

Without looking into it, is it possible that your script creating a new blocking window (msgbox) when it has received the PBT_APMSUSPEND is not allowed?

Try with a consolewrite.

[JohnOne]

And look into PowerCreateRequest and related API's.