layui二级联动

 <label class="layui-form-label">报考层次:</label>
  <div class="layui-input-inline layui-form">
    <select name="student_Level"  lay-verify="required"  lay-filter="college" class="select">
     <option value=""></option>
     <option >专本套读</option>
     <option >双学位</option>
      </select>
    </div>
 </div>
 <div class="layui-form-item">
  <div class="layui-inline">
  <label class="layui-form-label">报考专业:</label>
    <div class="layui-input-inline">
      <select name="student_Major" lay-verify="required" >
      </select>
</div>
layui.use(['element','form'], function(){
    var element = layui.element;
    var form = layui.form;
    var  layer = layui.layer;
 
 form.on('select(college)', function (data) {
         var message=$("select[name=student_Level").val();
         
         if(message=="双学位"){
           var html="<option value=''></option><option>教育学</option><option>管理学</option>";
           $("select[name=student_Major]").empty();
           $("select[name=student_Major]").append(html);
               form.render('select');
         }else if(message=="专本套读"){
           var html1="<option value=''></option><option>学前教育</option><option>护理学</option><option>英语</option><option>工程管理</option><option>计算机科学与技术</option><option>旅游管理</option><option>财务管理</option><option>环境设计</option><option>市场营销</option><option>动画</option>";
           $("select[name=student_Major]").empty();
           $("select[name=student_Major]").append(html1);
               form.render('select');
         }
      });
});