function movedown(){
var iens6=document.getElementById;
var speed=10;
var crossobj=document.getElementById("content");
var contentheight=crossobj.offsetHeight;
if (iens6&&parseInt(crossobj.style.top)>=(contentheight*(-1)+300)) crossobj.style.top=parseInt(crossobj.style.top)-speed+"px";

movedownvar=setTimeout("movedown()",20);
}

function dgmoveup(){

var iens6=document.getElementById;
var speed=10;
var crossobj=document.getElementById("content");
var contentheight=crossobj.offsetHeight;
if (parseInt(crossobj.style.top)<=0) crossobj.style.top=parseInt(crossobj.style.top)+speed+"px"

//else if (ns4&&crossobj.top<=0)
//crossobj.top+=speed

moveupvar=setTimeout("dgmoveup()",20);

}

function getcontent_height(){
//var crossobj=document.getElementById("content");
var contentheight=document.getElementById("content").offsetHeight;
//contentheight=crossobj.offsetHeight;
}
//window.onload=getcontent_height();