Flash as2 Help with my Actionscript File

programming flash
1

Cannot figure out WHY this is not working. I created a Actionscript File called Hero.as. I have a movieclip with no instance name called Hero. Hero is set to export for actionscript. Inside of my Hero movieclip, on frame two is my animation movieclip.
So what I am doing is when the key RIGHT is pressed, the character moves right! This is REALLY easy if I am NOT using an Actionscript file. However, using the same code inside of my actionscript file, I cannot get the animation to play. The character moves right, but no animation. Here is the code:

class Hero extends MovieClip
{
var velocity;

function onLoad()
{
    velocity = 10;
}

function onEnterFrame()
{
    if(Key.isDown(Key.RIGHT))
    {
        _root.hero.gotoAndPlay(2);
        _x = _x + velocity;            
    }
}

}