如何用jQuery和AJAX实现省市区三级联动选择？

<select id="province"></select><select id="city"></select><select id="area"></select>

// 省份$.ajax({    url: '/api/province',    method: 'GET',    success: function(data) {        $.each(data, function(index, item) {            $('#province').append($('<option>', {                value: item.id,                text: item.name            }));        });    }});// 市$('#province').change(function() {    var provinceId = $(this).val();    $.ajax({        url: '/api/city/' + provinceId,        method: 'GET',        success: function(data) {            $('#city').html('');            $.each(data, function(index, item) {                $('#city').append($('<option>', {                    value: item.id,                    text: item.name                }));            });            $('#city').trigger('change');        }    });});// 区$('#city').change(function() {    var cityId = $(this).val();    $.ajax({        url: '/api/area/' + cityId,        method: 'GET',        success: function(data) {            $('#area').html('');            $.each(data, function(index, item) {                $('#area').append($('<option>', {                    value: item.id,                    text: item.name                }));            });        }    });});