MooTools Fx.Slide duration

Question

I use MooTools Fx.Slide to open / close different containers on the same page.
Some containers hold only little text , others very long text .

When I set the duration to, say, 500 ...

var thisSlider = 
    new Fx.Slide(item.getElement('.main'), 
    {duration: 500}
);

The small container opens slowly, the big one is rushing up and down very fast...

see http://jsfiddle.net/6H9f5/1/

How can I have the containers open at the same "average speed" ?

Answer 1

Here is a option, more of a hack. Not sure it qualifies as an answer :)

    var itemMain = item.getElement('.main');
    var thisHeight = itemMain.getSize().y;
    var speed = 500 + (thisHeight * 3);
    console.log(speed); // to check the values proportion
    var thisSlider = new Fx.Slide(itemMain,{
        duration: speed
    });

Fiddle