Как сделать форму прозрачной?

Private Declare Function GetWindowLong Lib 'user32' Alias 'GetWindowLongA' (ByVal hWnd As Long, _ ByVal nIndex As Long) As Long
Private Declare Function SetWindowLong Lib 'user32' Alias 'SetWindowLongA' (ByVal hWnd As Long, _ ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Declare Function SetLayeredWindowAttributes Lib 'user32' (ByVal hWnd As Long, _
ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
 
Private Const LWA_ALPHA = &H2
Private Const GWL_EXSTYLE = (-20)
Private Const WS_EX_LAYERED = &H80000
 
Dim pp As Byte
Dim Ret As Long
Ret = GetWindowLong(frm.hWnd, GWL_EXSTYLE) 'получаем стиль окна
Ret = Ret Or WS_EX_LAYERED 'добавляем в стиль заслоённость
SetWindowLong hWnd, GWL_EXSTYLE, Ret
SetLayeredWindowAttributes frm.hWnd, 0, pp, LWA_ALPHA 'делаем прозрачным, где pp-прозрачность от 0 до 255