History back button

alt_history_back.js

$('a.history-back').click(function() {
    history.back();
    return false;
  });

history_back.js

// Back link.
if (document.referrer.indexOf(window.location.hostname) != -1) {
  $('#block-boxes-history-back').show();
  $('a.history-back:not(.processed)').click(function(event) {
    event.preventDefault();
    parent.history.back();
  }).addClass('processed');
}