XMLHTTPRequest will fail if internet connection uses proxy server.

The XMLHTTPRequest will fail if you have proxy configured. we need use WinHttp instead of it. Refer the code pasted below.

if(sProxyIPAddress.Length != 0)
{
WinHttp.WinHttpRequest xmlhttp = new WinHttp.WinHttpRequest();
//Accessing the web service using Get method
xmlhttp.Open("GET", "http://www.webservicex.net/CurrencyConvertor.asmx/ConversionRate?FromCurrency=" + sfromCurrencyCode + "&ToCurrency=" + sBaseCurrency , null);
xmlhttp.SetProxy(2,sProxyIPAddress, null);
xmlhttp.Send(null);
xmlresult.loadXML(xmlhttp.ResponseText);
}
else
{
//Accessing the web service using Get method
MSXML2.XMLHTTP30Class xmlhttp = new MSXML2.XMLHTTP30Class();
xmlhttp.open("GET", "http://www.webservicex.net/CurrencyConvertor.asmx/ConversionRate?FromCurrency=" + sfromCurrencyCode + "&ToCurrency=" + sBaseCurrency, false, null, null);
xmlhttp.send(null);
xmlresult.loadXML(xmlhttp.responseText);
}