wow = new WOW( { animateClass: 'animated', offset: 100 } ); wow.init(); var userAgent = navigator.platform; //alert(userAgent); if(userAgent.substring(0,3) == "Mac") { document.getElementsByTagName('body')[0].className+=' mac' } else if (userAgent.substring(0,3) == "Win") { document.getElementsByTagName('body')[0].className+=' win' } else { document.getElementsByTagName('body')[0].className+=' nope' } /*var obj = document.getElementById("header"); var topVal = parseInt(obj.style.top, 10); obj.style.top = (topVal + 300) + "px";*/ var heroHeight = document.getElementById('header').offsetHeight; //alert(heroHeight);