(function($){$.fn.viewportChecker=function(useroptions){var options={classToAdd:'visible',
offset: 100,
callbackFunction: function(elem){}};$.extend(options, useroptions);var $elem=this,
windowHeight=$(window).height();this.checkElements=function(){var scrollElem=((navigator.userAgent.toLowerCase().indexOf('webkit') !=-1) ? 'body' :'html'),
viewportTop=$(scrollElem).scrollTop(),
viewportBottom=(viewportTop+windowHeight);$elem.each(function(){var $obj=$(this);if ($obj.hasClass(options.classToAdd)){return;}
var elemTop=Math.round( $obj.offset().top )+options.offset,
elemBottom=elemTop+($obj.height());if ((elemTop < viewportBottom) && (elemBottom > viewportTop)){$obj.addClass(options.classToAdd);options.callbackFunction($obj);}});};$(window).scroll(this.checkElements);this.checkElements();$(window).resize(function(e){windowHeight=e.currentTarget.innerHeight;});};})(jQuery);