as i have stated in my comment.. you cannot set variable as none.. set is as empty.
var $filterClass = "";
and the plugins is using
if ($.browser.msie || (typeof ($.fn.scale) == 'undefined')) {
$.browser
is removed in jquery 1.9 so using older version of jquery works..
however it is recommend against using this property; please try to use feature detection instead (see jQuery.support). jQuery.browser may be moved to a plugin in a future release of jQuery.