[Moo] Event args noob

[netSQL]

I normally use jssignals(it's great) for events, I am new to mootools,
but do like it.

Here is my code, it just displays the x/y of the mouse click.
 var onClick = function (el) {
    console.log('c',el.offsetX, el.offsetY); }

stageCanvas.addEventListener('click',onClick,false);
//stageCanvas.addEvent('click',onClick.pass(stageCanvas),false);

addEventListenerworks, addEvent does not. It says 'undefined'.
I do not want the inaner unnamed function for many reasons, one is not
testing.

How do I pass an argument to a function w/ MooTools?

Vic