Hi Everyone i got the solution for the above Question.
GO to http://webservicex.net, this is providing a WebService for ExchangeRate
Here is the code what i did.
Add service Reference in your Client Application
http://www.webservicex.net/CurrencyConvertor.asmx
Then Create the proxy Object in your Client Application
CurrencyExchange.CurrencyConvertor exchangerate = new CurrencyExchange.CurrencyConvertor();
double exchangevalue;
if (DropDownListcurrencies.SelectedValue == "UAE Dhiram")
{
exchangevalue = exchangerate.ConversionRate(CurrencyExchange.Currency.INR,CurrencyExchange.Currency.AED);
resultuae = result * Convert.ToDecimal(exchangevalue);
}