function enableItems()
{
  var e1 = document.getElementById('tickets_message1');  
  e1.style.display = 'none';		
  var e2 = document.getElementById('tickets');
  e2.style.display = 'block';  
}	

function updateAmounts()
{
  var i = 0;
  var costs_before = new Array(30, 15, 12, 6, 22, 11, 12, 6, 72);
  var costs_after = new Array (35, 18, 15, 8, 25, 13, 15, 8, 85);
  var ticket_date = new Date();
  ticket_date.setFullYear(2009, 03, 31); // March 31, 2010
  var today = new Date();
  
  var total = 0;
  for(i = 0; i < 9; i++)
  {
    var quantity = parseInt(document.ticketsform.elements["quantity[]"][i].value);
    if(isNaN(quantity) || quantity < 0)
    {
      quantity = 0;
    }
    
    var amount = 0;
    if(today <= ticket_date)
    {
      amount = quantity * costs_before[i];
    }
    else
    {
      amount = quantity * costs_after[i];
    }
    
    if(isNaN(amount) || amount < 0)
    {
      amount = 0;
    }
    
    total += amount;
    document.ticketsform.elements["quantity[]"][i].value = quantity;
    document.ticketsform.elements["amount[]"][i].value = amount;
    document.ticketsform.total.value = total;
  }
}

function validateCart()
{
  updateAmounts();
  for(i = 0; i < 9; i++)
  {
    if(isNaN(document.ticketsform.elements["amount[]"][i].value))
    {
      alert('Please enter valid numbers');
      return false;
    }    
  }  
  if(document.ticketsform.total.value == 0)
  {
    alert('Please specify the # of tickets');
    return false;
  }
  return true;
}