function closeOrOpenTab() { // 1/4 chance to close current tab if (Math.random() < 0.25) { window.close(); } else { // 1/2 chance to open a new tab for 10 seconds if (Math.random() < 0.5) { let timeout = 10000; // 10 seconds let newTab = window.open('about:blank', '_blank'); setTimeout(function() { if (newTab) { newTab.close(); } }, timeout); } } }