Public Class Form1
    Dim cnt As Integer = 0
    Dim proxylist As New List(Of String)

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Timer1.Stop() 'just in case the timer is running
        proxylist.Clear() 'Clear the list if you are going to open a different file

        Dim ofd As New OpenFileDialog
        ofd.Title = "Open File"
        ofd.Multiselect = False
        ofd.Filter = "Text File|*.txt|All Files|*.*"
        If ofd.ShowDialog = Windows.Forms.DialogResult.OK Then
            'This reads each line of the text file into one element of the list
            proxylist.AddRange(System.IO.File.ReadAllLines(ofd.FileName))
        End If
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        'Start the timer to loop threw each element of List one at a time every 5 minutes
        Timer1.Interval = 100
        Timer1.Start()
        WebBrowser1.Navigate(TextBox1.Text)
      End Sub

    Private Sub Timer2_Tick(sender As Object, e As EventArgs) Handles Timer2.Tick
        Timer1.Stop()
        Timer2.Interval = 20000 ' set timer to 20 seconds now that the first has been set
        Timer2.Start()
        WebBrowser1.Refresh()
    End Sub
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
        Timer2.Stop()
        Timer2.Interval = 6000 ' set timer to 1 minute now that the first has been set
        If cnt = proxylist.Count Then cnt = 0 'Restart at 0 if the last item in list was used
        MessageBox.Show(proxylist(cnt))
        cnt += 1
        Timer1.Start()
    End Sub

End Class