easyui框架对tab的限制提示

        var $tab = $(‘#tabs‘);
        var tabCount = $tab.tabs(‘tabs‘).length;
        var hasTab = $tab.tabs(‘exists‘, title);
        var aaaa;
        var content;
        if ((tabCount <= nav_MaxCount) || hasTab) {

            btn_cancelClick();
            aaaa = $(‘#tabs‘).id;
            $(‘#tabs‘).tabs(‘close‘, title);

             content = ‘<iframe scrolling="auto" frameborder="0" id="‘ + id + ‘" src="‘ + url + ‘" style="width:100%;height:100%;"></iframe>‘;
            $(‘#tabs‘).tabs(‘add‘, {
                title: title,
                content: content,
                closable: true
            });

        }
       else
       $.messager.confirm("系统提示", ‘您当前打开了太多的页面，如果继续打开，会造成程序运行缓慢，无法流畅操作！‘, function (b) {
                if (b) {
                    btn_cancelClick();
                    aaaa = $(‘#tabs‘).id;
                    $(‘#tabs‘).tabs(‘close‘, title);
                    content = ‘<iframe scrolling="auto" frameborder="0" id="‘ + id + ‘" src="‘ + url + ‘" style="width:100%;height:100%;"></iframe>‘;
                    $(‘#tabs‘).tabs(‘add‘, {
                        title: title,
                        content: content,
                        closable: true
                    });

                }
            });