Is it possible to detect current page is in alt-tab?
This code works only if a new tab in browser is opened:

(function() {

  var hidden = hidden;



  // Standards:

  if (hidden in document)

    document.addEventListener(visibilitychange, onchange);

  else if ((hidden = mozHidden) in document)

    document.addEventListener(mozvisibilitychange, onchange);

  else if ((hidden = webkitHidden) in document)

    document.addEventListener(webkitvisibilitychange, onchange);

  else if ((hidden = msHidden) in document)

    document.addEventListener(msvisibilitychange, onchange);

  // IE 9 and lower:

  else if (onfocusin in document)

    document.onfocusin = document.onfocusout = onchange;

  // All others:

  else

    window.onpageshow = window.onpagehide

    = window.onfocus = window.onblur = onchange;



  function onchange (evt) {

    var v = visible, h = hidden,

        evtMap = {

          focus:v, focusin:v, pageshow:v, blur:h, focusout:h, pagehide:h

        };



    evt = evt || window.event;

    if (evt.type in evtMap)

      document.body.className = evtMap[evt.type];

    else

      document.body.className = this[hidden] ? hidden : visible;

  //console.log(this[hidden] ? hidden : visible);

  }



  // set the initial state (but only if browser supports the Page Visibility API)

  if( document[hidden] !== undefined )

    onchange({type: document[hidden] ? blur : focus});

})();

But this code does detect neither new window of the browser nor alt-tab into any other programm. Is it possible to detect it? Or in jQuery?

EDIT
New page means Ctrl(cmd)+N (new window) hotkey. The code above can not detect this. Alt(cmd)+tab to another program - impossible to detect too.
The code above can only detect Ctrl(cmd)+T (new tab)

EDIT
I want to detect when a user return to my site from another application. That is, if a user closes any tab (e.g., by Ctrl+W) and returns to my site I can detect this action using the script above. But if a user returns to my site from another application (e.g., by Alt+Tab) the script doesn't work because window.onfocus will not be fired! That is,

 window.onpageshow =

 window.onpagehide = window.onfocus = window.onblur 

doesn't work for Alt+Tab action. Is it more clear?