How to Add Disappearing Effect To Forms in Visual Basic

This code demonstrates the use of SetLayeredWindowAttributes, GetWindowLong& SetWindowLong API calls. You need a timer on the form called "Timer1". Timer1 is enabled by default, so with the Load Event of the form it'll start ticking....
It'll make the form more transparent with each tick. 255 means no transparency, 0 means 100% transparent. When the form is 100% transparent Timer1 will unload it and load the "Main" form (I assume frmMain is the Main Form or any form you want to show after unloading it).
The only problem with this code is that Windows98 & ME does not support SetLayeredWindowAttributes API, so it won't work on these Operating Systems. You can use GetVersionEx API to determine the OS Version....
Copy the code below in the form you want to add the effect to.

Option Explicit
Dim Trans As Integer
Private Const LWA_COLORKEY = 1
Private Const LWA_ALPHA = 2
Private Const LWA_BOTH = 3
Private Const WS_EX_LAYERED = &H80000
Private Const GWL_EXSTYLE = -20
Private Declare Function SetLayeredWindowAttributes Lib "user32" _
(ByVal hwnd As Long, ByVal color As Long, ByVal x As Byte, _
ByVal alpha As Long) As Boolean
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 GetWindowLong Lib "user32" Alias _
"GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Sub SetTrans(hwnd As Long, Trans As Integer)
Dim Tcall As Long
Tcall = GetWindowLong(hwnd, GWL_EXSTYLE)
SetWindowLong hwnd, GWL_EXSTYLE, Tcall Or WS_EX_LAYERED
SetLayeredWindowAttributes hwnd, RGB(255, 255, 0), Trans, LWA_ALPHA
Exit Sub
End Sub
Private Sub Form_Load()
frmMain.Show
frmMain.Enabled = False
Timer1.Interval = 1
Trans = 255
SetTrans Me.hwnd, Trans
End Sub
Private Sub Timer1_Timer()
If Trans <> 0 Then
Trans = Trans - 1
End If
SetTrans Me.hwnd, Trans
If Trans = 0 Then
frmMain.Enabled = True
Unload Me
End If
End Sub