//specify speed of scroll (greater=faster)
var speed=5;

var crossobj=document.getElementById("content");
var contentheight=crossobj.offsetHeight;

function movedown(){
var speed=5;

var crossobj=document.getElementById("content");
var contentheight=crossobj.offsetHeight;

if (parseInt(crossobj.style.top)>=(contentheight*(-1)+100))
crossobj.style.top=parseInt(crossobj.style.top)-speed+"px"
movedownvar=setTimeout("movedown()",20)
}

function moveup(){
var speed=5;
var crossobj=document.getElementById("content");
var contentheight=crossobj.offsetHeight;

if (parseInt(crossobj.style.top)<=0)
crossobj.style.top=parseInt(crossobj.style.top)+speed+"px"
moveupvar=setTimeout("moveup()",20)
}

function getcontent_height(){
var speed=3;
var crossobj=document.getElementById("content");
var contentheight=crossobj.offsetHeight;

contentheight=crossobj.offsetHeight
window.onload=getcontent_height
}