protected void shopBasketCheckout_OnServerClick(object source，EventArgs e)
{
　string postData = "";
　postData += "currency_code=GBP";
　postData += "&cmd=_cart";
　postData += "&business=youremailaddress@yourdomain.net";
　postData += "&upload=1";
　postData += "&cancel_return=www.davidmillington.net";
　DataTable dtBasket = getBasketDt();
　double total = 0.00;
　for(int i = 0; i < dtBasket.Rows.Count; i++)
　{
　　postData += "&item_name_" + (i + 1) + "=" +
　　dtBasket.Rows[i]["name"];
　　postData += "&quantity_" + (i + 1) + "=" +
　　dtBasket.Rows[i]["quantity"];
　　postData += "&amount_" + (i + 1) + "=" +
　　Convert.ToDouble(dtBasket.Rows[i]["price"]);
　　total += (Convert.ToDouble(dtBasket.Rows[i]
["price"]) * Convert.ToInt32(dtBasket.Rows[i]["quantity"]));
　　if(i == dtBasket.Rows.Count - 1)
　　{
　　　postData += "&shipping_" + (i + 1) + "=" + calcDeliveryCost(total);
　　}
　　else
　　{
　　　postData += "&shipping_" + (i + 1) + "=0.00";
　　}
　　postData += "&shipping2_" + (i + 1) + "=0.00";
　　postData += "&handling_" + (i + 1) + "=0.00";
　}
　postData += "&handling=" + calcDeliveryCost(total);
　byte[] data = Encoding.ASCII.GetBytes(postData);
　HttpWebRequest ppRequest = (HttpWebRequest)
WebRequest.Create("https://www.paypal.com/cgi-bin/webscr");;
　ppRequest.Method = "POST";
　ppRequest.ContentType = "application/x-www-form-
　urlencoded";
　ppRequest.ContentLength = data.Length;
　//发送
　Stream ppStream = ppRequest.GetRequestStream();
　ppStream.Write(data， 0， data.Length);
　ppStream.Close();
　//接收
　HttpWebResponse ppResponse = (HttpWebResponse)ppRequest.GetResponse();
　StreamReader sr = new StreamReader(ppResponse.GetResponseStream());
　string strResult = sr.ReadToEnd();
　sr.Close();
　//输出到屏幕
　Response.Clear();
　Response.Write(strResult);
　Response.End();
}