Small plugin that reports the size of the browser's scrollbars in pixels.

jquery.scrollbarWidth.js

/*!
 * jQuery Scrollbar Width v1.0
 * 
 * Copyright 2011, Rasmus Schultz
 * Licensed under LGPL v3.0
 * http://www.gnu.org/licenses/lgpl-3.0.txt
 */

(function($){

$.scrollbarWidth = function() {
  if (!$._scrollbarWidth) {
     var $body = $('body');
    var w = $body.css('overflow', 'hidden').width();
    $body.css('overflow','scroll');
    w -= $body.width();
    if (!w) w=$body.width()-$body[0].clientWidth; // IE in standards mode
    $body.css('overflow','');
    $._scrollbarWidth = w;
  }
  return $._scrollbarWidth;
};

})(jQuery);

Unfortunately I have no access to the main window code, It can be any third party page embedding my page.
Do you know how to access the main page from embedded iframe page code?

Thanks
Marco

well, window.opener or window.top - but if your page is embedded from another domain, you most likely won't be allowed access.

Thanks, I will try
Marco

Great stuff, seems to work well and so simple. :-)