this is an another way:
<html>
<head>
<title>Echo</title>
<style type="text/css">
#result{
border: 1px solid #000000;
min-height: 250px;
max-height: 100%;
padding: 5px;
font-family: sans-serif;
font-size: 12px;
}
</style>
<script type="text/javascript" lang="ja">
function start(){
function echo(text){
lastResultAreaText = document.getElementById('result').innerHTML;
resultArea = document.getElementById('result');
if(lastResultAreaText==""){
resultArea.innerHTML=text;
}
else{
resultArea.innerHTML=lastResultAreaText+"</br>"+text;
}
}
echo("Hello World!");
}
</script>
</head>
<body onload="start()">
<pre id="result"></pre>
</body>