scroll page to an element in the document or a top-pixel position

scrollTo

// http://stackoverflow.com/questions/8917921/cross-browser-javascript-not-jquery-scroll-to-top-animation/23844067#23844067
// e = element to scroll to or top position in pixels, d = time to scroll in ms
function scrollTo(e,d){if(d>=0){var h=document.documentElement;if(h.scrollTop===0){var t=h.scrollTop;++h.scrollTop;h=t+1===h.scrollTop--?h:document.body}typeof e==="object"&&(e=e.offsetTop);scrollToX(h,h.scrollTop,e,0,1/d,20)}}

/*
e = scrollable element
a = initiall scrollable element position (from)
b = height to scroll to (to)
t = lerp from a to b (0 - 1)
v = speed. input 1 / time to scroll
s = repeat every 's' miliseconds
*/
function scrollToX(e,a,b,t,v,s){function F(){t<0||t>1||v<=0||(k=t-1,e.scrollTop=a-(a-b)*(k*k*k+1),t+=v*s,setTimeout(F,s))}F()}