Problem with Actionscript 3.0

[Mrs Spider]

Hi,

I am trying to create a series of invisible buttons, within a Flash movie, that link to various URLs. I have created a button on one layer and an action on a separate layer but I can't get it to work.

The Action reads:
gotaq_btn.addEventListener(MouseEvent.CLICK, buttonClickHandler);
function buttonClickHandler(event:MouseEvent):void {
navigateToURL(new URLRequest("http://www.gotaqchallenge.com"));
}

The error message I get is:
'The class or interface 'MouseEvent' could not be loaded.'

I am using Flash CS3 Pro (Actionscipt 3.0)

I have been trying to get this to work for the best part of the day so am hoping someone out there will tell me where I'm going wrong and put me out of my misery!

Can anyone help??

Thanks

[bellyscratch]

you havent got any other events called 'buttonClickHandler' have you?