easyui的combobox模糊搜索

<tr>
    <th>测试名称:</th>
    <td>
        <select data-options="" class="easyui-combobox" prompt="请选择" id="reg_name" name="reg_name"></select>
    </td>
</tr>

$(function () {
    $("#reg_name").combobox({

        valueField: 'id',
        textField: 'db_name',
        panelWidth: 200,
        panelHeight: 'auto',
        onChange: function (values, o) {
            debugger;
           var valuess= $('#reg_name').combobox('getText');
            if (values != "") {
                var url = prefix + "/allAdvunionidList?valuess="+valuess;
                $("#reg_name").combobox("reload", url);
            }
        }
    })

});