validate Bank sort code
<p>Is in the format XX-XX-XX (where X=a number). If entered without the dashes, format accordingly. If any of the digits are missing (e.g. 01-2-22, or 11556), a warning should be displayed to check the details.Please tell how to validate this</p>

<p>Thankyou</p>

<pre><code>          string str_sortcode = txt_sortcode.Text;
            Regex r = new Regex(@"12-22-34");
            Match match1 = r.Match(str_sortcode);
            if (match1.Success)
            {

            }
            else
            {
                MainContent_updPanelError.Visible = true;
                lblerrr.Visible = true;
                lblerrr.Text = "Please enter a valid Bank Sort Code. For example: 12-22-34";
                return false;
            }
</code></pre>
