var elcopy = {
  start: function()
  {
    if ($('copy_button')) Event.observe('copy_button', 'click', elcopy.docopy);
  },
  docopy: function(e)
  {
    $$('.copy').each(function (e) {
      $(e.getAttribute('copy')).value = e.value;
    });

    return false;
  }
}

Event.observe(window, 'load', elcopy.start);