recolic / Lululemon order page print

// ==UserScript==
// @name         Lululemon order page print
// @version      0.1
// @description  Removes header and footer from lululemon order page
// @author       Recolic
// @match        https://shop.lululemon.com/help/purchase-details/*
// @icon         data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==
// @grant        none
// @license      MIT
// ==/UserScript==

(function() {
    'use strict';

    function cleanup () {
    let ar = document.getElementsByClassName('OneLinkNoTx');
for (var i = 0; i < ar.length; ++i) {
  if(ar[i].localName == "header") {
    ar[i].remove();
    break;
  }
}
document.getElementById('footer').remove();
    }

    // Your code here...
    window.addEventListener('load', function() {
cleanup();
}, false);
    const interval = setInterval(function() {
   cleanup();
 }, 5000);


})();