Option Explicit

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 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 = (-20)
Private Const WS_EX_LAYERED = &H80000

Private Const LWA_ALPHA = &H2

Public Sub Form_SetStyle(ByVal hWnd As Long)
  Dim nStyle As Long

  nStyle = GetWindowLong(hWnd, GWL_EXSTYLE)

  nStyle = nStyle Or WS_EX_LAYERED
  SetWindowLong hWnd, GWL_EXSTYLE, nStyle
End Sub

Public Sub Form_SetAlphaValue(ByVal hWnd As Long, _
       ByVal bAlpha As Byte)
  SetLayeredWindowAttributes hWnd, 0, bAlpha, LWA_ALPHA
End Sub

Public Sub Form_FadeIn(ByVal hWnd As Long, _
       Optional ByVal iStep As Integer = 1)
  Dim iAlpha As Integer

  For iAlpha = 0 To 255 Step iStep
    SetLayeredWindowAttributes hWnd, 0, iAlpha, LWA_ALPHA
    DoEvents
  Next
End Sub

Public Sub Form_FadeOut(ByVal hWnd As Long, _
       Optional ByVal iStep As Integer = 1)
  Dim iAlpha As Integer

  For iAlpha = 255 To 0 Step -iStep
    SetLayeredWindowAttributes hWnd, 0, iAlpha, LWA_ALPHA
    DoEvents
  Next
End Sub

Option Explicit

Private Sub Form_Load()
  Form_SetStyle Me.hWnd
  Me.Visible = True
  Form_FadeIn Me.hWnd, 1
End Sub

Private Sub cmdSetAlphaValue_Click()
  Dim varAlpha As Variant

  varAlpha = Val(Text1.Text)
  Select Case varAlpha
    Case Is < 100: varAlpha = 100
    Case Is > 255: varAlpha = 255
    Case Else
  End Select

  Form_SetAlphaValue Me.hWnd, varAlpha
End Sub

Private Sub Form_Unload(Cancel As Integer)
  Form_FadeOut Me.hWnd
  End
End Sub