Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button2.Click
        MessageBox.Show("Button2_Click")
    End Sub
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
         ' .... 
        MessageBox.Show("Button1_Click")
        Me.Button2.PerformClick()
    End Sub