get image from html content

Hi all,
I write code as :

Regex r = new Regex(this.textbox1.Text);
        Match m = r.Match(this.SearchStringTextBox.Text);       

        while (m.Success)
        {
           Response.Write(m.Value);
           Response.Write("<br>");
            m = m.NextMatch();
        }

this.textbox1.Text="<img[^>]* src=\"([^\"]*)\"[^>]*>"
this.SearchStringTextBox.Text = " I get html content ..........."

Now i don't get of any results ? Any one show me errors ?
Thank you very much.

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