vb.net > listbox ile atlama yapmadan butona bastırma

Dim sitesayisi As Integer 
      Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load 
          sitesayisi = 0 
      End Sub

 Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click 
          Me.WebBrowser2.Navigate("facebook.com/" & Convert.ToString(ListBox1.Items.Item(sitesayisi))) 
          Button2.Enabled = False 
          Button3.Enabled = True 
          Button1.Enabled = False 
   
      End Sub

 Private Sub WebBrowser2_DocumentCompleted(ByVal sender As System.Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser2.DocumentCompleted 
          Dim allelements As HtmlElementCollection = WebBrowser2.Document.All 
          For Each webpageelement As HtmlElement In allelements 
              If WebBrowser2.Url.ToString = ("facebook.com/" & Convert.ToString(ListBox1.Items.Item(sitesayisi))) Then 
                  If webpageelement.GetAttribute("alt") = "Bu üyeyi beğenmek için tıkla." Then 
                  Else 
                      webpageelement.InvokeMember("click") 
                  End If 
              End If 
              sitesayisi = sitesayisi + 1 
          Next 
      End Sub