function searchLot()
{
  var regex = /^([\d]+)$/;
  var lot_number = document.lot_search.lot.value;

  if (regex.test(lot_number) != true)
  {
    alert('Please enter a valid lot number');
    return;
  }

  javascript:void(window.open('detail.php?lot='+lot_number, '', 'width=700, height=630, scrollbars=1'))
}