//创建xmlHttp对象var xmlHttp = null;function createXMLRequest( ){
var msxmlhttp = new Array(
'Msxml2.XMLHTTP.6.0',
'Msxml2.XMLHTTP.3.0',
'Msxml2.XMLHTTP',
'Microsoft.XMLHTTP');
for(var i = 0; i var xmlHttp;try {xmlHttp = new XMLHttpRequest()}catch(e){try {xmlHttp = new ActiveXObject("Msxml2.XMLHTTP")} catch(e){xmlHttp = new Act