I am doing with static currency (AUD-->INR)

Place a button on _.aspx page. @ button click event do this..

protected void btnShow_Click(object sender, EventArgs e)

{

decimal apiRate = 0;

string firstCcode="AUD";

string lastCcode="INR"

decimal amount=1;

apiRate = ExchangeRateFromAPI(amount, firstCurrencyCode, currencyCode);

//use the apiRate;

}

private decimal ExchangeRateFromAPI(decimal amount,string firstCcode, string lastCcode)

{

try

{

WebClient web = new WebClient();

const string urlPattern = "http://finance.yahoo.com/d/quotes.csv?s={0}{1}=X&f=l1";

string url = String.Format(urlPattern, firstCcode, lastCcode);

// Get response as string

string response = new WebClient().DownloadString(url);

// Convert string to number

decimal exchangeRate = decimal.Parse(response, System.Globalization.CultureInfo.InvariantCulture);

return exchangeRate;

}

catch (Exception ex){

return 0;

}

}