var speed = 120;
var move = 4; 
var x = 0; 
var y = 0; 
var nx = 0; 
var ny = 0; 

function scroll(){ 
window.scrollBy(0, move);
var rep = setTimeout("scroll()", speed); 

if(document.all){ 
    x = document.body.scrollLeft || document.documentElement.scrollLeft;
    y = document.body.scrollTop || document.documentElement.scrollTop;
    } 
    else if(document.layers || document.getElementById){ 
        x = pageXOffset; 
        y = pageYOffset; 
        } 

if(nx == x && ny == y){ 
    clearTimeout(rep); 
    } 
    else{ 
       nx = x; 
       ny = y; 
       } 

} 

function pageMove(){
  window.scrollTo(0,0);
}