JS Challenge #1

Self Evaluating JS
Here is an example:

<div id=toexec>
"Hello World<!--".replace("Hello World",'"Goodbye World"');//-->"
</div>
<button onclick=exec()>Exec</button>
<script>

function exec(){
      var n = document.getElementById('toexec');
      n.innerHTML = eval(n.innerHTML);
}
</script>

The Challenge
Actually there isn't one. I just really like that code

http://qaa.ath.cx/pexec.html