Asp.net Page Render Does not include images

Protected Overrides Sub Render(ByVal writer As HtmlTextWriter)

        Dim sb As New StringBuilder()
        Dim hWriter As New HtmlTextWriter(New StringWriter(sb))
        MyBase.Render(hWriter)
        Dim PageResult As String = sb.ToString()
        writer.Write(PageResult)
        Dim file As New System.IO.StreamWriter(Server.MapPath("~\UploadedDocs\") & "InvoiceDetail" & Request.QueryString("ClientJobID") & ".html")
            file.WriteLine(PageResult)
            file.Close()
 End Sub