textarea
<br><textarea id=a></textarea>
<br>div
<div id=b></div>
<input type=button onclick="f();" value=refresh>
<script>
function o(id) {return document.getElementById(id);}
function f() {o('b').innerHTML = o('a').value;}
setInterval('f()',300);
</script>
Nebo muzes pouzit to same s location.href='url'.