GetExchangeRates

//GetExchangeRates
error :

static void getExchangeRates(Args _args)
{
    int         curPos, endPos, startPos;
    TextBuffer  tb = new TextBuffer();
    System.Net.WebRequest webRequest;
    System.Net.WebResponse webResponse;
    str page;
    System.IO.StreamReader streamReader;

    try
    {
        webRequest = System.Net.WebRequest::Create("http://www.x-rates.com/d/INR/table.html");

        // this will throw an webexception if cannot be reached.
        webResponse = webRequest.GetResponse();
        streamReader = new System.IO.StreamReader(webResponse.GetResponseStream());

        tb.setText('');
        page = streamReader.ReadToEnd();

        streamReader.Close();

        tb.setText(page);
        curpos   = 1;
        startPos = 1;
        tb.regularExpressions(false);

        tb.find('<a href="/d/INR/EUR/graph120.html" class="menu">', curpos);

        startpos = tb.matchPos();

        tb.find('</a>&nbsp;</font></td>', startpos);
        endpos = tb.matchPos();

        page = tb.subStr(startpos, endpos - startpos);
        info(strFmt("1 EUR = %1 INR",strreplace(page,'<a href="/d/INR/EUR/graph120.html" class="menu">','')));

        // Close the webResonse
        webResponse.Close();
    }
    catch(Exception::CLRError)
    {
        throw error(AifUtil::getClrErrorMessage());
    }
}