EasyUI_前台js_省市县三级联动

1、html:

 <td class="tdl">所属城市</td>
    <td class="td_detail">
    <input id="sheng" />
    &nbsp<input id="city" />
    &nbsp<input id="xian" />
 </td>

2、js

  $("#sheng").combobox({
            url: '../Ajax/Customer.ashx?action=getCityByCode&code=0',
            valueField: 'codeID',
            textField: 'name',
            onLoadSuccess: function () {
            $('#sheng').combobox('select', '---请选择---');
            },
            onChange: function () {
                var sheng = $("#sheng").combobox("getValue");
                var tag = 1;
                $("#city").combobox({
                    url: "../Ajax/Customer.ashx?action=getCityByCode&code=" + sheng,
                    valueField: 'codeID',
                    textField: 'name',
                    onLoadSuccess: function () {
                    $('#city').combobox('select', '---请选择---');
                    },
                    onChange: function () {
                        var city = $("#city").combobox("getValue");
                        $("#xian").combobox({
                            url: "../Ajax/Customer.ashx?action=getCityByCode&code=" + city,
                            valueField: 'codeID',
                            textField: 'name',
                            onLoadSuccess: function () {
                            $('#xian').combobox('select', '---请选择---');
                            }
                        })
                    }
                })
            }
        })