$.post submits data and returns data method instance in json format

<script>function getType(url, id) {
     $.post(url, {'id': id}, function(res) {
         $("input[name='formula']").val(res.finally);
         $("input[name='formula2']").val(res.proportion);
     }, 'json');
 }</script>

    public function gettype(){
        $where['id'] = trim($_POST['id']);        $info = M('formula')->where($where)->find();        echo json_encode($info);exit;
    }

<input name="formula" class="form-control" type="text"><input name="formula" class="form-control" type="text"><select name=&#39;type&#39;  select" onchange="getType(&#39;Deal/gettype&#39;, this.value);">
    <option value="海口">海口</option>
    <option value="海口">海口</option>
    <option value="海口">海口</option></select>