WebBrowser コントロールを使用し、URL を見ずにどの frame かを識別することは可能ですか？

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace TestApp
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            webBrowser1.Navigate(フレームになったページのURL);
        }

        private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {
            Console.WriteLine("e.Url = " + e.Url);
        }
    }
}

Public Class Form1



    Private WithEvents wb1 As New WebBrowser



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



        wb1.Dock = DockStyle.Fill

        Me.Controls.Add(wb1)



        wb1.Navigate("C:\Documents and Settings\デスクトップ\HTML\FrameSet.html")



    End Sub



    Private Sub wb1_documentComp(ByVal s As Object, ByVal e As WebBrowserDocumentCompletedEventArgs) Handles wb1.DocumentCompleted



        Console.WriteLine(s.ToString + "::" + e.Url.ToString)





    End Sub

End Class

<frameset rows="50,*">

	<frameset cols="50,*">

		<frame src="http://www.google.com">

		<frame src="http://www.yahoo.co.jp">

	</frameset>

	<frame src="http://www.goo.ne.jp">

</frameset>

        private void webBrowser1_DocumentCompleted(object sender, WebBrowserDocumentCompletedEventArgs e)
        {
            if (webBrowser1 == sender)
            {
                Console.WriteLine("同じ");
            }
            else
            {
                Console.WriteLine("違う");
            }
            Console.WriteLine("e.Url = " + e.Url);
        }

        private void webBrowser1_Navigating(object sender, WebBrowserNavigatingEventArgs e)
        {
            Console.WriteLine("Navigating = " + e.Url 
                + ", TargetFrameName = " + e.TargetFrameName + ", " + e.Cancel);
        }