/**
 * ajax无刷新二级联动下拉菜单(省市联动)
 *
 * @author      arcow <arcow@126.com>
 * @version     1.0
 * @lastupdate  2005-12-29
 *
 */
var http_request = false;

function send_request(url,method){
    //初始化、指定处理函数、发送请求的函数
    http_request = false;
    //开始初始化XMLHttpRequest对象
    if(window.XMLHttpRequest){ //Mozilla 浏览器
        http_request = new XMLHttpRequest();
        if (http_request.overrideMimeType){//设置MiME类别
            http_request.overrideMimeType('text/xml');
        }
    }
    else if (window.ActiveXObject){ // IE浏览器
        try{
            http_request = new ActiveXObject("Msxml2.XMLHTTP");
        }catch(e){
            try{
                http_request = new ActiveXObject("Microsoft.XMLHTTP");
            }catch(e){}
        }
    }
    if (!http_request) { // 异常，创建对象实例失败
        window.alert("XMLHttpRequest object sample can't be created.");
        return false;
    }
    switch(method){
        case 1: http_request.onreadystatechange = processRequest1;break;//选择操作函数
        case 2: http_request.onreadystatechange = processRequest2;break;
        case 3: http_request.onreadystatechange = processRequest3;break;
    }
    // 确定发送请求的方式和URL以及是否同步执行下段代码
    http_request.open("GET", url, true);
    http_request.send(null);
}

// 处理返回信息的函数
function processRequest1(){//操作函数1,调入country
    if (http_request.readyState == 4){ // 判断对象状态
        if (http_request.status == 200){ // 信息已经成功返回，开始处理信息
            document.getElementById("statusTxt").innerHTML="";
            addOptionGroup("country",http_request.responseText);
        }else{ //页面不正常
            alert("There is an error from the requested page.");
        }
    }else {//只要未读取完成
        //document.getElementById("statusTxt").innerHTML="Data loading……";
    }
}

function processRequest2(){//操作函数2,调入state
    if (http_request.readyState == 4){ // 判断对象状态
        if (http_request.status == 200){ // 信息已经成功返回，开始处理信息
            document.getElementById("statusTxt").innerHTML="";
            addOptionGroup("state",http_request.responseText);
        }else{ //页面不正常
            alert("There is an error from the requested page.");
        }
    }else{//只要未读取完成
        //document.getElementById("statusTxt").innerHTML="Data loading……";
    }
}

function processRequest3(){//操作函数3,输入country state
    if (http_request.readyState == 4){ // 判断对象状态
        if (http_request.status == 200){ // 信息已经成功返回，开始处理信息
            document.getElementById("statusTxt").innerHTML="";
            document.getElementById("district").value=http_request.responseText;
        }else{ //页面不正常
            alert("There is an error from the requested page.");
        }
    }else{//只要未读取完成
        //document.getElementById("statusTxt").innerHTML="Data loading……";
    }
}

function loadCountry(){//载入Country
    send_request("select.server.php?action=country",1); //服务端处理程序,操作函数
}

function loadState(){//载入State
    document.getElementById("district").value="";//清空文本框
    send_request("select.server.php?action=state&id="+document.getElementById("country").value,2);
}

function inputDistrict(){//向文本框输入选定的country state
    send_request("select.server.php?action=district&id="+document.getElementById("country").value+"&id1="+document.getElementById("state").value,3);
}