Anyone help on this simple task?

programming flash
1 
buttons = ["b1", "b2", "b3", "b4", "b5", "b6"]

buttons[0].onRollOver = over;
buttons[0].onRollOut = out;

function over() {
	this.gotoAndPlay(2);
}
function out() {
	this.gotoAndPlay(7);
}

If I wanted an array surely this would work, as it outputs b1 fine with a trace, but how come the button does not seem to pick it up?

Any ideas