How To Detect Browser Close Event In Firefox?

How to detect browser close event in Firefox browser? I want to do some clean up process in server side and we maintaining last logout time. To achieve this need fire an ajax call

Solution 1:

Use onbeforeunload

window.onbeforeunload = function (e) {

  e = e || window.event;

  // For IE and Firefox prior to version 4
  if (e) {
    e.returnValue = 'Any string';
  }

  // For Safari
  return 'Any string';
};

Solution 2:

var closedWindow = function() {
    //code goes here
};

if (window.addEventListener) {
    window.addEventListener('unload', closedWindow, false);
} else if (window.attachEvent) {
    // pre IE9 browser
    window.attachEvent('onunload', closedWindow);
}

Solution 3:

window.addEventListener('unload',fn,false);