利用WebBrowser去抓取原始碼的值

小舗有人問下面的問題，記得以前曾寫過類似功能

目前我想寫個取得股票的程式,用法是利用WebBrowser去抓取原始碼搜尋,想請教假如原始碼你想要的值剛好在<B>...</B>之間,各位都是如何去抓取中間的值呢??

程式如下

Public Class Form1

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

        TextBox1.Text = "http://www.hep-tech.com.tw/"

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        TextBox2.Text = Nothing

        If TextBox1.Text <> String.Empty Then

            Me.WebBrowser1.Navigate(TextBox1.Text)

        End If

    End Sub

    Private Sub WebBrowser1_DocumentCompleted(ByVal sender As System.Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted

        DisplayElem()

    End Sub

    Private Sub DisplayElem()

        If (WebBrowser1.Document IsNot Nothing) Then

            Dim Elems As HtmlElementCollection

            Dim WebDoc As WebBrowser = WebBrowser1

            Elems = WebDoc.Document.GetElementsByTagName("b")

            Dim tmpStr As String = Nothing

            For Each elem As HtmlElement In Elems

                TextBox2.Text += (elem.InnerText) & vbNewLine

            Next

        End If

    End Sub

End Class