// ajax 对象function ajaxObject() {    var xmlHttp;    try {        // Firefox, Opera 8.0+, Safari        xmlHttp = new XMLHttpRequest();        }     catch (e) {        // Internet Explorer        try {                xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");            } catch (e) {            try {                xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");            } catch (e) {                alert("您的浏览器不支持AJAX！");                return false;            }        }    }    return xmlHttp;} // ajax post请求：function ajaxPost ( url , data , fnSucceed , fnFail , fnLoading ) {    var ajax = ajaxObject();    ajax.open( "post" , url , true );    ajax.setRequestHeader( "Content-Type" , "application/x-www-form-urlencoded" );    ajax.onreadystatechange = function () {        if( ajax.readyState == 4 ) {            if( ajax.status == 200 ) {                fnSucceed( ajax.responseText );            }            else {                fnFail( "HTTP请求错误！错误码："+ajax.status );            }        }        else {            fnLoading();        }    }    ajax.send( data ); }