How I can select a value from RadioButtonList which filled from a webservice?

please could you help me? i have  a problem in this code


protected void ddlCurrencyFrom_SelectedIndexChanged(object sender, EventArgs e)
{
if (string.IsNullOrEmpty(ddlCurrencyFrom.SelectedValue) == false)
{
net.webservicex.www.CurrencyConvertor obj = new net.webservicex.www.CurrencyConvertor();

double d = obj.ConversionRate(ddlCurrencyFrom.SelectedValue, Currency.YER);

TextBox1.Text = d.ToString();



PopupControlExtender.GetProxyForCurrentPopup(this.Page).Commit(ddlCurrencyFrom.SelectedValue);
}


i have a RadioButtonList of currencies which i filled it from webservicex.com
How I can select a value and convert it to Rial Yemeni(YER)


the problem in this code:


double d = obj.ConversionRate(ddlCurrencyFrom.Sele ...