Как прервать цикл с помощью кнопки в окне GUI ?

#include <GUIConstantsEx.au3>
#include <WindowsConstants.au3>
#include <StaticConstants.au3>
#include <GuiButton.au3>
#include <GDIPlus.au3>

HotKeySet('{F1}', 'stop')

Global $Form2 = GUICreate("Form1", 399, 300)
GUISetBkColor(0x000000)
Global $Button = GUICtrlCreateButton("PUSK", 50, 250, 130, 22,$SS_CENTERIMAGE)
GUICtrlSetStyle(-1,$BS_CENTER)
GUICtrlSetCursor (-1, 0)
Global $Button2 = GUICtrlCreateButton("STOP", 220, 250, 130, 22,$SS_CENTERIMAGE)
GUICtrlSetStyle(-1,$BS_CENTER)
GUICtrlSetCursor (-1, 0)
Global $Form1 = GUICreate("", 399, 200, 0, 0, BitOR($DS_SETFOREGROUND,$WS_CHILD,$WS_BORDER),-1,$Form2) 
GUISetState(@SW_SHOW, $Form1)
GUISetState(@SW_SHOW, $Form2)

_GDIPlus_Startup()
$hGraphic = _GDIPlus_GraphicsCreateFromHWND($Form1)
$hBrush1 = _GDIPlus_BrushCreateSolid()

Global $i = 0

While 1
Local $nMsg = GUIGetMsg()
Switch $nMsg
	Case $GUI_EVENT_CLOSE
		_GDIPlus_BrushDispose($hBrush1)
		 _GDIPlus_GraphicsDispose($hGraphic)
		 _GDIPlus_Shutdown()
	   Exit
   Case $Button
       pusk()
   Case $Button
       stop()
EndSwitch
WEnd

Func pusk()
	$i = 0
Do
    _GDIPlus_BrushSetSolidColor($hBrush1, '0x' & Hex(Random(0xFF000000, 0xFFFFFFFF, 1)))
    _GDIPlus_GraphicsFillRect($hGraphic, Random(1, 390), Random(1, 290), 10, 10, $hBrush1)
	Sleep(10)
Until $i = 1000
EndFunc

Func stop()
	$i = 1000
EndFunc

Func stop()
    $i = 1000
EndFunc

;...
While 1
	Local $nMsg = GUIGetMsg()
	Switch $nMsg
		Case $GUI_EVENT_CLOSE
			_GDIPlus_BrushDispose($hBrush1)
			 _GDIPlus_GraphicsDispose($hGraphic)
			 _GDIPlus_Shutdown()
		   Exit
	   Case $Button
		   AdlibRegister('pusk', 10)
	   Case $Button2
		   AdlibUnRegister('pusk')
	EndSwitch
WEnd

Func pusk()

	_GDIPlus_BrushSetSolidColor($hBrush1, '0x' & Hex(Random(0xFF000000, 0xFFFFFFFF, 1)))
	_GDIPlus_GraphicsFillRect($hGraphic, Random(1, 390), Random(1, 290), 10, 10, $hBrush1)
EndFunc
;...

; ...
;~ Global $i = 0

While 1
Local $nMsg = GUIGetMsg()
Switch $nMsg
    Case $GUI_EVENT_CLOSE
      _GDIPlus_BrushDispose($hBrush1)
      _GDIPlus_GraphicsDispose($hGraphic)
      _GDIPlus_Shutdown()
      Exit
   Case $Button
      pusk()
;~    Case $Button
;~        stop()
EndSwitch
WEnd

Func pusk()
  Local $i = 0
  Do
    _GDIPlus_BrushSetSolidColor($hBrush1, '0x' & Hex(Random(0xFF000000, 0xFFFFFFFF, 1)))
    _GDIPlus_GraphicsFillRect($hGraphic, Random(1, 390), Random(1, 290), 10, 10, $hBrush1)
    Sleep(10)
    If GUIGetMsg() = $Button2 Then Return
  Until $i = 1000
EndFunc

;~ Func stop()
;~     $i = 1000
;~ EndFunc

...
If GUIGetMsg() = $Button2 Then Return 
If GUIGetMsg() = $Button3 Then Return 
If GUIGetMsg() = $Button4 Then Return 
If GUIGetMsg() = $Button5 Then Return 
и т. д. ...

Switch GUIGetMsg()
      case $Button2, $Button3, $Button4
        Return
    EndSwitch