.NET [LEARNING VB] Made a useless app | Suggestions for imporvement? [LEARNING VB]

Code
Imports System.IO

Imports System.Net



Public Class Form1



    Dim thread1 As System.Threading.Thread



    Private Sub leach1()

      If ListBox1.Items.Count <> 0 Then

      Dim sourcestring As String = New WebClient().DownloadString("http://" & ListBox1.Items.Item(0))

      Dim index As Integer = sourcestring.LastIndexOf("</textarea>")

      Dim string2 As String = sourcestring.Remove(index)

      Dim output As String = string2.Substring(string2.LastIndexOf("event)") + 8)

      Dim array() As String = output.Split(Environment.NewLine)

      Label1.Text = "Status: Grabbing Paste..."

      For Each line As String In array

            TextBox1.AppendText(CStr(line & Environment.NewLine))

      Next

      Label1.Text = "Status: Finnished!"

      Else

      MessageBox.Show("Please enter a URL!", "No URL entered", MessageBoxButtons.OK, MessageBoxIcon.Error)

      End If

    End Sub



    Private Sub exportpaste()

      If TextBox1.Text <> "" Then

      Dim svdlg As SaveFileDialog = New SaveFileDialog

      svdlg.Filter = "Text Files (*.txt)|*.txt|All Files (*.*)|*.*"

      svdlg.ShowDialog()

      Dim sw As StreamWriter = New StreamWriter(svdlg.FileName)

      sw.Write(TextBox1.Text)

      sw.Close()

      Else

      MessageBox.Show("No paste data to export!", "No data to export!", MessageBoxButtons.OK, MessageBoxIcon.Error)

      End If

    End Sub



    Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click

      ListBox1.Items.Clear()

    End Sub



    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

      Add_URL.Show()

    End Sub



    Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click

      thread1 = New System.Threading.Thread(AddressOf leach1)

      thread1.Start()

    End Sub



    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load

      Me.CheckForIllegalCrossThreadCalls = False

    End Sub



    Private Sub Button5_Click(sender As Object, e As EventArgs) Handles Button5.Click

      TextBox1.Clear()

      Label1.Text = "Status: Idle"

    End Sub



    Private Sub Button6_Click(sender As Object, e As EventArgs) Handles Button6.Click

      exportpaste()

    End Sub

End Class