TextBox1.SelectionStart = TextBox1.Text.Length
TextBox1.ScrollToCaret()

    Private Sub dependency_onchange(ByVal sender As Object, ByVal e As  _
      SqlNotificationEventArgs)
        If CType(Me, ISynchronizeInvoke).InvokeRequired Then
            Dim d As New OnChangeEventHandler(AddressOf dependency_onchange)
            CType(Me, ISynchronizeInvoke).BeginInvoke(d, New Object() {sender, _
              e})
 
 
        End If
 
        Dim dependency As SqlClient.SqlDependency = CType(sender,  _
          SqlClient.SqlDependency)
 
        RemoveHandler dependency.OnChange, AddressOf dependency_onchange
 
        getData()
 
    End Sub

    Private Sub getData()
        Using connection As New SqlConnection(My.Settings.connstring)
            connection.Open()
            Using command As New SqlCommand("select message from msg where" & _
              "fromuid = '" & dgv_msg.Item(1, dgv_msg.CurrentRow.Index).Value & _
              "' and touid = '" & usern & "' or fromuid = '" & usern & "' and" & _
              "touid = '" & dgv_msg.Item(1, dgv_msg.CurrentRow.Index).Value & _
              "'", connection)
                Dim dependency As New SqlClient.SqlDependency(command)
                AddHandler dependency.OnChange, AddressOf dependency_onchange
 
                TextBox1.Text = CType(command.ExecuteScalar(), String)
 
                TextBox1.SelectionStart = TextBox1.Text.Length
                TextBox1.ScrollToCaret()
            End Using
        End Using
    End Sub