通用ajax初始化代码

jameszhao83

function   createXmlHttpRequest(){var xmlhttp = null;try{//Firefox, Opera 8.0+, Safari           xmlhttp=new XMLHttpRequest();}catch(e){//IEIE7.0以下的浏览器以ActiveX组件的方式来创建XMLHttpRequest对象var MSXML = ['MSXML2.XMLHTTP.6.0','MSXML2.XMLHTTP.5.0','MSXML2.XMLHTTP.4.0','MSXML2.XMLHTTP.3.0','MSXML2.XMLHTTP','Microsoft.XMLHTTP'];  for(var n = 0; n < MSXML.length; n ++){    try{      xmlhttp = new ActiveXObject(MSXML[n]);      break;    }catch(e){}}  }return xmlhttp;} 普遍性的创建连接等
function loadpro(){var xhr=createXmlHttpRequest();xhr.onreadystatechange=function(){if(xhr.readyState==4 ||(xhr.status==200 || xhr.status==304)){alert(xhr.responseText);var ret=eval("("+xhr.responseText+")");alert("ret lenght:"+ret.length);var s="";for(var i=0;i<ret.length;i++){alert("retX="+ret[i]);s+="<option>"+ret[i]+"</option>";}alert("s:"+s);document.getElementById("pro").innerHTML=s;}}xhr.open("get","servlet/ProvLoad",true);xhr.send(null);}