gistfile1.js

function updateTotalCost() {
  var total = 0.00;
  $('shoppingCart').select('td.cost').each(function(td) {
    total += parseFloat(td.innerHTML)
  })
  total_cell = $('total_cell')
  total_cell.update(total.toFixed(2))
  new Effect.Highlight(total_cell)
}