Making function to control nav, prototyping

1

i have this site i’m making a lot of navigation items that all follow the same type of animation.

i want to have a centralized location where i can change how the animation looks and have it affect all the items.

so far i had an idea like this:


function changeNav(navitem:MovieClip):Void {
     navitem.tween("_x", 2, "easeOutSine");
}

then i call it with a rollover button


nav_mc.main_butt.onRelease = function():Void {
     changeNav(main);
}

basically i try a trace function and it returns undefined so I’m guessing there’s something wrong in my syntax. any suggestions? its like its not passing the movieclip name as a variable let alone executing the tween function.