Following Doug Winnie's Event Handlers (episode 13)

Question

Hello:
I am following Doug Winnie's Event Handlers (episode 13). When I follow his example:
var blueSquare = new BlueSquare();
blueSquare.x=50;
blueSquare.y=50;
addChild(blueSquare);
blueSquare.addEventListener(MouseEvent.MOUSE_DOWN,onClick);
blueSquare.addEventListener(MouseEvent.MOUSE_OVER,onOver);
function onClick(e:MouseEvent):void{
  trace("The blue square was clicked.");
function onOver(e:MouseEvent):void{
  trace("Mouse Over");
I get two blue squares instead of one on the stage. I am using flash professional CC 2014 on windows 7
Thanks in advance for your help.

Answer 1

There is nothing in that code that would cause two to be added to the display unless you are moving into the same frame twice.
How can you tell you get two instead of one?  One would be sitting atop the other so you would not see the two.  Did you happen to leave a copy of it on the stage?
Try adding that code in a new file and copy the BlueSquare object into its library and see if the same problem exists.