ASP与XML的问题

username=request.Form("username")
from=request.Form("from")
email=request.Form("email")
if username <>"" and from <>"" and email <>"" then
datesource=server.MapPath("1.xml")
set objXML=server.CreateObject("microsoft.FreeThreadedXMLDOM")
objXML.async = False
objXML.load(datesource)
set objRootsite=objXML.documentelement.selectsingleNode("Newlist")
if objRootsite.hasChildNodes then
id=objRootsite.lastChild.firstChild.text+1
else
id=1
end if
brstr=chr(13)&chr(10)&chr(9)
XMLnode=" <list>"&brstr&" <id>"&id&" </id> <username>"&username&" </username> <from>"&from&" </from> <email>"&email&" </email> </list>"

set objXML2=server.CreateObject("microsoft.FreeThreadedXMLDOM")
objXML2.load(XMLnode)
objXML2.async=false
set rootNumnode=objXML2.documentElement
objRootsite.appendChild(rootNumnode) ''就是这里
objXML.save(datesource)
set objXML=NOTHING
set objXML2=nothing
response.Write"留言成功"
response.end
end if


Microsoft VBScript 运行时错误 (0x800A0005)
无效的过程调用或参数: 'objRootsite.appendChild'
/asp/untitled5.asp, 第 24 行
我在这里看到有人说用rootNumnode.CloneNode(true)也不行啊,说没有对象rootNumnode
为什么会这样的错误,谁能给告诉我啊,晕死了