X-admin框架中change事件失效如何实现省市区三级联动

Uncaught TypeError: layui.form is not a function的错误

我现在使用的就是X-admin1.1版本的后台模板，在实现了三级联动的情况下想套上去结果发现会报上面的错误等等

在html中select标签需要加上 lay-filter="" 如下代码中所示，后面才能选中到这个select，form.render();是为了渲染这个改变的下拉框

<select lay-filter="demo1" name="hostel_id1" id="hostel_id1" style="width:150px;">
		<option>请选择</option>
		{volist name="hostel_list" id="hostel"}
		    <option value="{$hostel['name']}">{$hostel['name']}</option>
		{/volist}                                                
</select>



<script type="text/javascript">
	layui.use(['form', 'jquery'],function(){
    var $ = layui.jquery;
    var form = layui.form();
    form.on('select(test1)', function(data){
    	var province_id = data.value;
  		$.get("{:url('index/Admin/getcity')}",{'province_id':province_id},function(data){
            var data = JSON.parse(data);
            console.log(data);
            console.log(data['city'].length);
            var option=$("<option></option>");
                 var $select = $("#city_id");
                for(var i=0;i<data['city'].length;i++){
                   $select.append("<option value=" + data['city'][i]['name'] + ">" + data['city'][i]['name'] + "</option>");
                }
            form.render();   //渲染select
        })
	});

});
	layui.use(['form', 'jquery'],function(){
    var $ = layui.jquery;
    var form = layui.form();
    form.on('select(test2)', function(data){
    	var province_id = $('#province_id').val();
        var city_id=data.value;
        $.get("{:url('index/Admin/getdistrict')}",{'city_id':city_id,'province_id':province_id},function(data){
            var data = JSON.parse(data);
            console.log(data);
            var option=$("<option></option>");
                 var $select = $("#district_id");
                for(var i=0;i<data['area'].length;i++){
                   $select.append("<option value=" + data['area'][i] + ">" + data['area'][i] + "</option>");
                }
                form.render();
            })
        }); 
});


	layui.use(['form', 'jquery'],function(){
    var $ = layui.jquery;
    var form = layui.form();
    form.on('select(demo1)', function(data){
    	var province_id = data.value;
  		$.get("{:url('index/Admin/getcity1')}",{'province_id':province_id},function(data){
            var data = JSON.parse(data);
            console.log(data);
            
            var option=$("<option></option>");
                 var $select = $("#hostel_id2");
                for(var i=0;i<data['building'].length;i++){
                   $select.append("<option value=" + data['building'][i]['name'] + ">" + data['building'][i]['name'] + "</option>");
                }
            form.render();
        })
	});

});