地区三级联动

今天有人问我用js怎么实现地区三级联动???? what???这是基本功好伐，话不多说 看代码

// 初始化地址列表
addressInit();

function addressInit() {
        $.get('order.php?act=address', function (resp) {
            // 测试是否存在收货地址
            if (0 == resp.data.length) {
                return false;
            }
            //展示地址
            $('#al_01').empty();

            $.each(resp.data, function (i, address) {
                var option = '<li>';
                option += '<span>'+address.consignee+'</span>';
                option += '<span id='+address.address_id+'>'+address.r1_title+' '+address.r2_title+' '+address.r3_title+' '+address.address+' '+address.mobile;
                option += '</span>';
                option += '<a href="javascript:del_add('+address.address_id+')">删除</a>';
                option += '<a href="javascript:edit_add('+address.address_id+')" class="click_pop">修改</a>';
                option += '</li>';
                $('#al_01').append(option);
            });
        }, 'json');
    }


function setRegion(id, level) {
        // 下个级别
        var next = +level + 1;

        // 设置最大地区
        var maxLevel = 3;

        // ajax获取子地区
        $.get('order.php?act=child', {region_id: id}, function (resp) {
            $('#input-address-region_id_' + next + '>option:gt(0)').remove();
            $.each(resp.region, function (i, region) {     // option += address.is_last == '1' ? ' selected' : '';
                var option = '<option value="' + region.region_id + '">';
                option += region.region_name;
                option += '</option>';
                // 加入select(next)
                $('#input-address-region_id_' + next).append(option);
            });
        }, 'json');

        //清空 后续的select
        for (var i = next + 1; i <= maxLevel; ++i) {
            $('#input-address-region_id_' + i + '>option:gt(0)').remove();
        }

    }



$(function () {
        // 初始化1级地区
        setRegion(1, 0);
        // 绑定select的change事件
        $('select[id^=input-address-region_id_]').change(function () {
            // 请选择, 不触发
            if ('' == $(this).val()) {
                return;
            }
            setRegion($(this).val(), $(this).data('level'));
        });
})

 1             <li>
                <label class="left"><b>*</b> 所在地区：</label>
                <div class="formlisttext" id="add">
                    <select class="small-input" name="region_id_1" id="input-address-region_id_1" data-level="1">
                        <option value=""> 请选择 </option>
                    </select>
                    <select class="small-input" name="region_id_2" id="input-address-region_id_2" data-level="2">
                        <option value=""> 请选择 </option>
                    </select>
                    <select class="small-input" name="region_id_3" id="input-address-region_id_3" data-level="3">
                        <option value=""> 请选择 </option>
                    </select>
                </div>
            </li>

function action_child(){
    # 获取会员id
    $db = $GLOBALS['db'];
    $ecs = $GLOBALS['ecs'];
    $user_id = $_SESSION['user_id'];
    if(isset($_GET['address_id'])){
        # 地址列表
        $add_sql = "select a.*, r1.region_name as r1_title, r2.region_name as r2_title, r3.region_name as r3_title  from"
            .$ecs->table('user_address')." as a left join "
            .$ecs->table('region')." as r1 on a.province=r1.region_id left join "
            .$ecs->table('region')." as r2 on a.city=r2.region_id left join "
            .$ecs->table('region')." as r3 on a.district=r3.region_id "
            ." where a.user_id=".$user_id." AND a.address_id=".$_GET['address_id'];
        $address_list = $db->getRow($add_sql);
    }

    if(isset($_GET['region_id'])){
        $id = $_GET['region_id'];
        $sql = "select * from".$ecs->table('region').' where parent_id='.$id;
        $rows = $db->getAll($sql);
    }else{
        $sql = "select * from".$ecs->table('region');
        $rows = $db->getAll($sql);
    }

    $arr = array('add'=>$address_list,'region'=>$rows);
    echo json_encode($arr);
    die;
}



function action_address()
{
    # 获取会员id
    $db = $GLOBALS['db'];
    $ecs = $GLOBALS['ecs'];
    $user_id = $_SESSION['user_id'];

    # 地址列表
    $add_sql = "select a.*, r1.region_name as r1_title, r2.region_name as r2_title, r3.region_name as r3_title  from"
        .$ecs->table('user_address')." as a left join "
        .$ecs->table('region')." as r1 on a.province=r1.region_id left join "
        .$ecs->table('region')." as r2 on a.city=r2.region_id left join "
        .$ecs->table('region')." as r3 on a.district=r3.region_id "
        ." where a.user_id=".$user_id." and status=0";
    $address_list = $db->getAll($add_sql);
    echo json_encode(array('data' => $address_list));
}