window.addEvent('domready', function(){

  var i = 0;
  var max = $$('table#chart tr').length - 1;

  var td_sx;
  var td_dx;

  $$('table#chart tr').each(function(el){

    switch(i)
      {
      case 0:
        td_sx = new Element('td', {'html': '<img style="margin:0; padding:0" src="' + common_site_url() + '/img/chart/bg_thead_carrello_sx.gif" />',
          'styles': {
            'width': '10px',
            'padding': '0',
            'margin': '0',
            'background': '#fff'
          }
        });

        td_dx = new Element('td', {'html': '<img style="margin:0; padding:0" src="' + common_site_url() + '/img/chart/bg_thead_carrello_dx.gif" />',
          'styles': {
            'width': '10px',
            'padding': '0',
            'margin': '0',
            'background': '#fff'
          }
        });
        break;

      default:
        td_sx = new Element('td', {
          'styles': {
            'width': '10px',
            'padding': '0',
            'margin': '0'
          }
        });

        td_dx = td_sx;
        break;

      case max:
        td_sx = new Element('td', {'html': '<img style="margin:0; padding:0" src="' + common_site_url() + '/img/chart/bg_totale_carrello_sx.gif" />',
          'styles': {
            'width': '10px',
            'padding': '0',
            'margin': '0',
            'background': '#fff'
          }
        });

        td_dx = new Element('td', {'html': '<img style="margin:0; padding:0" src="' + common_site_url() + '/img/chart/bg_totale_carrello_dx.gif" />',
          'styles': {
            'width': '10px',
            'padding': '0',
            'margin': '0',
            'background': '#fff'
          }
        });
        break;
      }

    td_dx.inject(el, 'bottom');
    td_sx.inject(el, 'top');

    i++;
  });

});