//makesure you have a MovieClip in the Library exported for ActionScript with the class: Star
          //create a new variable and datatype it as a Star (the MovieClip you have in the library)
var newStar:Star;
 
          //add a mouseDown listener to the stage that will call the function addRemoveStar
stage.addEventListener(MouseEvent.MOUSE_DOWN, addRemoveStar);
             //BestPractice (no stage / weak reference):    this.addEventListener(MouseEvent.MOUSE_DOWN, addRemoveStar, false, 0, true);  
 
          //write the function addRemoveStar
function addRemoveStar(e:MouseEvent)
              //BestPractice(return void):     function addRemoveStar(e:MouseEvent):void
{
 
	       //create a variable named objectClicked and store the target of the MouseDown Event
	       //(it will either be the stage or something that has been added to the stage like a newStar)
	var objectClicked = e.target;
 
	       //create an if statement to find out if the target of the mouseDown event was the stage or a newStar
	if(objectClicked == stage)
	{
		       //when the target of the mouseDown event is the stage, create a new instance of the Star called newStar
		newStar= new Star;
 
		       //position the newStar at the x and y coordinates of the mouse
		newStar.x = mouseX;
		newStar.y = mouseY;
 
		       //add the newStar to the stage
		stage.addChild(newStar);
	}
	       //when the target of the mouseDown event is not the stage it means it is a newStar
	else
	{
		          //remove the newStar that was clicked (the target of the mouseDown event)
		stage.removeChild(objectClicked);
	}
}