Instance name question, help plz

programming flash
1

how do you declare various movieclip in 1 onEnterFrame?

for example:
[AS]
mc1.onRollOver = function() {
whitebox._x = this._x;
whitebox._y = this._y;
whitebox.gotoAndPlay(2);
};
mc2.onRollOver = function() {
whitebox._x = this._x;
whitebox._y = this._y;
whitebox.gotoAndPlay(2);
};
[/AS]

i have like over 20 mcs, how can i combine them to something like:
mc1,mc2,mc3,mc4.onEnterFrame

help needed! i even tried declaring Arrays!!