hi,
you might change the js to:
c = true;
lastPos = {
y1 : 0,
y2 : 0
}
el = hypeDocument.getElementById('menu');
sPos = el.getBoundingClientRect().top;
window.onscroll=function(){
wY = window.pageYOffset || (document.body.scrollTop || document.documentElement.scrollTop) ;
lastPos.y1 = lastPos.y2; lastPos.y2 = wY;
if(wY >= sPos && c){
c = false;
el.style.top = '0px';
el.setAttribute("class","sticky");
}
if (lastPos.y2 < lastPos.y1 && wY <= sPos && !c){
c = true;
el.style.top = sPos + 'px';
el.setAttribute("class","");
}
};