Tween Class

I am using the new flash Class easing tweens.
I imported the classes and then I made a function to take care of all my slides.


function slideMe(mc:MovieClip, prop:String, begin, finish, spd:Number) {
var tw = new Tween(mc, prop, Elastic.easeInOut, begin, finish, spd, true);
}

Then on my Button I call the function with this.


_root.slideMe(sectionPanel_intro, "_y", sectionPanel_intro._y, 443, 2);

This all works but the only parameter I can’t pass is the function, which would be easIn, easeOut, Strong.ease ect.
When I pass this it works but not with ease why is this.

Also is this the best way to approach this or is there a better way.

If I’m going to do it this way by having a wrap around function that takes care of the new class Tween then is there a way in this code of tweening the x and y at the same time without setting up another slideMe function for
x to be called at the same time as y.

Thanks,
Eric