function detectPopupBlocker() {
  var myTest = window.open("about:blank","","directories=no,height=100,width=100,menubar=no,resizable=no,scrollbars=no,status=no,titlebar=no,top=0,location=no");
  if (!myTest) {
    alert("A popup blocker was detected.  Some functions of this page will not work correctly!  If you wish to use the full functionality of this page, add this site to the "allow" list!");
  } else {
    myTest.close();
    alert("No popup blocker was detected.");
  }
}
window.onload = detectPopupBlocker;