Adding easing to a rotation function?

[Danger Madcow]

I have the following code:

function rotate(mc, dest){
	mc.onEnterFrame = function() {
		this._rotation = dest;
		if (Math.round(this._rotation) == [dest]) {
			trace("rotating done");
			this.onEnterFrame = undefined;
		}
	}
}

That moves the MC all at once, but how would I modify this so that it rotated and eased out?

Thanks in advance.