code: function(tabName){
      if (this.spreadsheet.activeTab === tabName){
        return;
      }
      switch(tabName) {
        case 'graph':
          D.hide(this.spreadsheet.container);
          D.removeClass(this.spreadsheet.tabs.data, 'selected');
          D.addClass(this.spreadsheet.tabs.graph, 'selected');
        break;
        case 'data':
          if (!this.spreadsheet.datagrid)
            this.spreadsheet.constructDataGrid();
          D.show(this.spreadsheet.container);
          D.addClass(this.spreadsheet.tabs.data, 'selected');
          D.removeClass(this.spreadsheet.tabs.graph, 'selected');
        break;
        default:
          throw 'Illegal tab name: ' + tabName;
      }
      this.spreadsheet.activeTab = tabName;
    }
docs: Shows the specified tab, by its name
  @todo make a tab manager (Flotr.Tabs)
  @param {String} tabName - The tab name