SO fiddle

Test Fiddle mainly for SO Questions

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8/themes/dot-luv/jquery-ui.css">
<textarea rows=10>Hi folks!
Do you like jQuery?
I do!</textarea><br/>
<button id=down>↓</button><button>↑</button>
<div></div>

CSS

div { white-space: pre; }

JavaScript

$("#down").click(function() {
    $("div").text($("textarea").val());
}).next().click(function () {
    $("textarea").val($("div").text());
});