easyui combobox默认选中项

 $("#OrderType").combobox({
                        url: "getType.asp?g=<%=session("grade")%>", //获取所有私有类型
                        valueField: "typeName",
                        textField: "typeName",
                        panelHeight: "auto",
                        editable: false, //不允许手动输入
                        onLoadSuccess: function () { //数据加载完毕事件
                            var data = $('#OrderType').combobox('getData');
                            if (data.length > 0) {
                                $("#OrderType").combobox('select', data[0].typeName);
                            }
                        }
                    });
                    
需要放到$(function(){............})才能在页面打开时加载commobox选项数据，用jquery的大家都懂的