easyui-combobox绑定回车事件注意事项

<select id="aucBrandNo" class="easyui-combobox"  name="aucBrandNo" style="width: 160px;"
     data-options="required:true,onHidePanel:function(){validateComboboxInputValue(this)}">
   </select>

//combobx数据的加载
function auctionSelect(aucBrandNos,aucBrandNo) {
    var aucBrandNoStr = '';
    $.each(aucBrandNos, function(index, temp) {
            aucBrandNoStr += '<option value=' + temp.key + '>' + temp.name.substring(1,4) + temp.name.substring(0,1)
                    + '</option>';
    });

    $('#aucBrandNo').html(aucBrandNoStr);
    $('#aucBrandNo').combobox({});
    $('#aucBrandNo').combobox('setValue', aucBrandNo);
    keyDownEventFun();//回车事件公共方法
};

function keyDownEventFun(){
    $('#aucBrandNo').textbox('textbox').keydown(function (event) {
        if (event.keyCode == 13) {
            //TODO
        }
    });

}