Fckeditor AND Ajax

Hello,

I have got the following code:

<script type="text/javascript" src="js/mootools.js"></script>
<script type="text/javascript">
window.addEvent('domready', function(){
$('registerForm').addEvent('submit', function(e) {
new Event(e).stop();
var log = $('log_res').empty().addClass('ajax-loading');
this.send({
update: log,
onComplete: function() {
log.removeClass('ajax-loading');
}
});
});
});
</script>

The problem is that its not working with fckeditor, just, if i take that code out. This code is to make the form validation.
Please advice.

Thank you,
Vitor Almeida