急求webservices错误捕捉方法,

我的源码:<%
Dim soapclient
Const WSDL_URL = "http://111.111.111.111/KFWEB/kfsf/studentdebt.asmx?wsdl"
set soapclient = Server.CreateObject("MSSOAP.SoapClient30")
soapclient.ClientProperty("ServerHTTPRequest") = True
soapclient.mssoapinit WSDL_URL
res = soapclient.GetStudentDebt(xh,Application("G_XqssXnd"))
'response.write(res)
%>
<%
dim xmlStr
xmlStr="<?xml version=""1.0"" encoding=""gb2312""?><root>"&res&"</root>"

set xml = server.createobject("Microsoft.XMLDOM")
xml.loadXML(xmlStr)
xml.async = false
set XmlXh = xml.selectsinglenode("//root/Student/StudentDebt/Xh")
set XmlXm = xml.selectsinglenode("//root/Student/StudentDebt/Xm")
set XmlJq = xml.selectsinglenode("//root/Student/StudentDebt/Jq")

if XmlXh.text=xh and XmlJq.text=1 then
nfzc=1
else
nfzc=0
end if

set xml = nothing
%>
问题:如果出现错误或连接超时的情况,请问如何捕捉.
我用的控件是SoapToolkit30.EXE