zoneminder/web/skins/classic/views/js/stats.js

function initPage() {
  var backBtn = $j('#backBtn');
  
  // Disable the back button if there is nothing to go back to
  backBtn.prop('disabled', !document.referrer.length);

  // Manage the BACK button
  document.getElementById("backBtn").addEventListener("click", function onBackClick(evt) {
    evt.preventDefault();
    window.history.back();
  });
  // Manage the REFRESH Button
  document.getElementById("refreshBtn").addEventListener("click", function onRefreshClick(evt) {
    evt.preventDefault();
    window.location.reload(true);
  });
}

$j(document).ready(function() {
  initPage();
});