OnPress -- only occur once

Uncategorized
1

I have an onPress event:

mRectangle.onPress = function():Void { 
twTween = new Tween(this, "_width",
  mx.transitions.easing.Regular.easeOut, 1220, 185, 25);    
}

I only want this event to happen once. I’m new to actionscript, but I imagine that there’s a quick and easy way to do that.

Can someone help me? I’m using AS 2.0.

Thanks.