,
                'spacer',
                {
                  extend: 'collection',
                  text: 'More',
                  buttons: [
                    {
                      extend: 'colvis',
                      text: 'Visible columns',
                      columns: [1,2,3,4,5,6,7],
                    },
                    {
                      text: (scrollY == '490px') ? 'Disable scrolling' : 'Enable scrolling',
                      action: function ( e, dt, node, config ) {
     