I need help

public class Comhoiriúnaigh extends World {

    private Actor clickedActor;
    
    private Actor a1;
    private Actor a2;
    
    public Comhoiriúnaigh() {
        super(640, 480, 1); 
        a1 = new Asal2();
        addObject (a1, 81, 73);
        a2 = new AsalWord(); 
        addObject (a2, 400, 73); 
    } 
    
    public void act() { 
        if (Greenfoot.mouseClicked(null)) { 
            MouseInfo mouse = Greenfoot.getMouseInfo(); 
            if (mouse.getActor() == a1) {
                if (clickedActor.equals(a2)) {
                    clickedActor = null;
                    removeObject(a1); 
                    removeObject(a2); 
                }
                else if (clickedActor == null) {
                    clickedActor = a1;
                }
                else {
                    clickedActor = null;
                }
            }
            else if (mouse.getActor() == a2) {
                if (clickedActor.equals(a1)) {
                    clickedActor = null;
                    removeObject(a1); 
                    removeObject(a2); 
                }
                else if (clickedActor == null) {
                    clickedActor = a2;
                }
                else {
                    clickedActor = null;
                }
            }
        } 
    }
}