var tempos=-1
function ruch(delta){
if (document.all){
currentpos=document.body.scrollTop+delta;
} else {
currentpos=window.pageYOffset+delta;
}
window.scroll(0,currentpos);
if(tempos==currentpos)
clearInterval(posun);
else
tempos=currentpos;
}

function stopit(){
clearInterval(posun);
}
function startit(delt){
if(delt=='gora')
posun=setInterval("ruch(-10)",20);
else
posun=setInterval("ruch(10)",20);
}