xmlhttp出现“数据还不可使用”错误

var xmlHTTP=new ActiveXObject("Microsoft.XMLHTTP");
xmlHTTP.Open("POST",'<%=request.getContextPath()%>/jsp/member/getExtvalue.jsp?mem_roleid=<%=request.getParameter("roleid")%>',false);
xmlHTTP.send("<extvalue attr_name=dd></extvalues>");
var template=new ActiveXObject("MSXML.DOMDocument");
template.loadXML(xmlHTTP.responseText);
var client=template.documentElement;
var satt_idvalues="";
var satt_ids="";
for(var i=0;i<client.childNodes.length;i++){
var attr_id=client.childNodes[i].getAttribute("attriid");
var attr_name=client.childNodes[i].getAttribute("attr_name");

}

上面代码第二行，xmlHTTP.Open("","","");第三个参数要加false，如果不加第三个参数就会出如标题错误