JS hack for header autohide on scroll for Jupiter WP theme

/** JS hack for header autohide on scroll for Jupiter WP theme - v0.3 - by rAthus **/
jQuery(document).ready(function($)
{
    var headerHeight = $('header').attr('data-height')*1;
    var mouseWheelEvt = (/Firefox/i.test(navigator.userAgent))?'DOMMouseScroll':'mousewheel';
    $(document).bind(mouseWheelEvt,function(e)
    {
        var evt = window.event||e;
            evt = evt.originalEvent?evt.originalEvent:evt;
        var delta = evt.detail?evt.detail*(-40):evt.wheelDelta;
        if (delta>0)
            $('header .mk-header-holder').stop(true).animate({'top':'0px'},100,'linear');
        else
            $('header .mk-header-holder').stop(true).animate({'top':'-'+headerHeight+'px'},100,'linear');
    });
    $(document).on('scroll',function(e)
    {
        if ($(window).scrollTop()*1+$(window).height()*1>$(document).height()*1-10)
            $('header .mk-header-holder').stop(true).animate({'top':'0px'},100,'linear');
    });
});