Really Frustrated

I'm new to flash, so its probably a really easy mistake but I've spent longer on this then making the rest of the whole FLA.

import flash.events.MouseEvent;

var request:URLRequest = new URLRequest("http://www.google.com");

Cristina_Btn.addEventListener(MouseEvent.MOUSE_UP, Funcao);
function Funcao(event: MouseEvent) :void {
navigateToURL(request);
}

Thats what I have down for my navigator, and it just won't work.
However if I change it to:

import flash.events.MouseEvent;

var request:URLRequest = new URLRequest("http://www.google.com");

Cristina_Btn.addEventListener(MouseEvent.MOUSE_DOW N,Funcao);
function Funcao(event: MouseEvent) :void {
navigateToURL(request);
}

It works like a charm.

This is on a button, so my issue is that I have an animation that triggers on the Button Down, which is getting completely skipped. I'd like them to be able to see if they hold it down, and only navigate once they release.

Hi!

just a heads up, you'll get more feedback if you post in the actionscript 3 section. ;)

Thx for the heads up :)