<html>
<head>
<title></title>
<style type='text/css'>
#one{
border:solid 1px green;
/*width:300px;
height:200px;*/
}
</style>
<script language='javascript'>
function fun2()
{
var object=document.getElementById('one');
if(document.body.scrollTop+document.body.clientHeight>object.offsetHeight+30+(document.body.clientHeight/2)){
alert('hello world');
window.onscroll=null;
}
}
window.onload=fun3;
function fun3()
{
var object=document.getElementById('one')
if(object.offsetHeight+30>document.body.clientHeight){
window.onscroll=fun2;
}
}
</script>
</head>
<body>
<div id='one'>
<script language='javascript'>
for(var i=0;i<100;i++)
{
document.write('3333<br/>');
}
</script>
</div>
<script language='javascript'>
for(var i=0;i<100;i++)
{
document.write('3333<br/>');
}
</script>
</body>
</html>
