window.onload=scroll;

function scroll(){
var img_html="<img src='../images/top_arrow.gif' onclick='sam()' width=20 style='cursor:hand;' height=20> "
div1.innerHTML=img_html;
div1.align="right";
//div1.style.cursor='hand';
div1.style.position='relative';
div1.style.display='none';
document.body.onscroll=move;
//document.getElementById("img1").onclick=sam;
}
function move(){
var rt=document.body.scrollLeft
var ht=document.body.scrollTop

if(ht>50){
document.getElementById("div1").style.display='';
document.getElementById("div1").style.posTop=document.body.scrollTop+120;
document.getElementById("div1").style.posLeft=document.body.scrollLeft;
}else{
document.getElementById("div1").style.display='none';
}

}
function sam(){
document.body.scrollTop=0;
}