Private Declare Function GetWindowLong Lib "user32.dll" Alias "GetWindowLongA" (ByVal hwnd As Long,ByVal nIndex As Long) As Long
Private Declare Function SetWindowLong Lib "user32.dll" Alias "SetWindowLongA" (ByVal hwnd As Long,ByVal nIndex As Long,ByVal dwNewLong As Long) As Long
Private Declare Function ShowWindow Lib "user32" (ByVal hwnd As Long,ByVal nCmdShow As Long) As Long
Private Declare Function SetLayeredWindowAttributes Lib "user32.dll" (ByVal hwnd As Long,ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long
 
Private Const GWL_EXSTYLE As Long = -20
Private Const WS_EX_LAYERED As Long = &H80000
Private Const LWA_ALPHA As Long = &H2
 
Public Function Transparant(hwnd As Long, percent As Integer,pil As Boolean)
	Dim before as Long
	before = GetWindowLong(hwnd,GWL_EXSTYLE)
	If pil = true then
		before = before Or WS_EX_LAYERED
		SetWindowLong hwnd, GWL_EXSTYLE, before
		SetLayeredWindowAttributes hwnd, 0, 255 * (percent / 100), LWA_ALPHA
	Else
		before = before And Not WS_EX_LAYERED
		SetWindowLong hwnd, GWL_EXSTYLE, before
	End If
End Function

Transparant Form1.hwnd, val(txtPercent.text), true