Public Class Form1
 
    Private b1 As New Bitmap("C:\windows\angler.bmp")
    Private b2 As New Bitmap("C:\windows\zapotek.bmp")
    Private flag As Boolean = False
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        Me.Label1.BackColor = Color.Transparent
        Me.Timer1.Interval = 2000
        Me.Timer1.Start()
    End Sub
 
    Private Sub Timer1_Tick(ByVal sender As Object, ByVal e As _
      System.EventArgs) Handles Timer1.Tick
        If flag = False Then
            flag = True
            Me.BackgroundImage = b1
        Else
            flag = False
            Me.BackgroundImage = b2
        End If
    End Sub
End Class