ajxser

<script>

   <span style="background-color: #c0c0c0;"> var xmlHttp;</span>//创建一个对象

    function queryDetail(id){

        if(window.ActiveXObject){

            xmlHttp = new ActiveXObject("MICROSOFT.XMLHTTP");

        }else if(window.XMLHttpRequest){

            xmlHttp = new XMLHttpRequest();

        }

 

        if(!xmlHttp){

            alert("没有获取到对象!");

            return;

        }

 

<span style="background-color: #00ff00;">        //由于javascript是没有办法连接数据库的，所以，需要通过后台语言

        //结合来连接数据库,那么这里就是把js从界面获取的值，传递给后台程序

        //xmlHttp.open()其实也就是链接到一个后台程序，把值传递过去

        //这其实是第一步</span>

        xmlHttp<span style="background-color: #ff0000;">.open("GET","queryById.php?id="+id,true);</span>

 

<span style="background-color: #00ff00;">        //这是第三步

        //这一步是一个回调函数，回调函数其实就和打电话代办事情是一个意思

        //这个回调函数其实就是状态改变的时候，js应该做什么事情</span>

        xmlHttp<span style="background-color: #ff0000;">.onreadystatechange = function()</span>{

            if(xmlHttp.readyState == 4){

                if(xmlHttp.status == 200){

                    var txt = xmlHttp.responseText;

                    var show = document.getElementById("show")

                    if(show){

                        show.innerHTML = "";

                        document.body.removeChild(show);

                    }else{

                        var d = document.createElement("div");

                        d.id = "show";

                        d.style.cssText="width:200px;height:300px;border:1px solid red;";

                        var strs = txt.split(",");

                        alert(strs);

                        for(var i=0;i<strs.length;i++){

                            d.innerHTML += strs[i] + "<br/>";

                        }

 

 

                        document.body.appendChild(d);

                    }

 

 

                }

            }

        }

 

 

   <span style="background-color: #00ff00;">     //注意，open()方法就仅仅只是打开了连接，并没有传递，所以需要send方法

        //这是第二步</span>

        xmlHttp.<span style="background-color: #ff0000;">send(null);</span>

 

    }

 

 

 

 

</script>