zoneminder/web/skins/classic/views/js/events.js.php

<?php
  global $filterQuery;
  global $sortQuery;
?>
//var openFilterWindow = <?php echo $_REQUEST['filter']?'true':'false' ?>;
var openFilterWindow = false;

var filterQuery = '<?php echo isset($filterQuery)?validJsStr(htmlspecialchars_decode($filterQuery)):'' ?>';
var sortQuery = '<?php echo isset($sortQuery)?validJsStr(htmlspecialchars_decode($sortQuery)):'' ?>';

var confirmDeleteEventsString = "<?php echo addslashes(translate('ConfirmDeleteEvents')) ?>";