支付接口代码如下：
<%
str = Request.Form & "&cmd=_notify-validate"
set objHttp = Server.CreateObject("Msxml2.ServerXMLHTTP")
objHttp.open "POST", "https://www.paypal.com/cgi-bin/webscr", false
objHttp.setRequestHeader "Content-type", "application/x-www-form-urlencoded"
...
