import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

public class Back extends Actor
{
    boolean Player1 = true;
 
    
    public void act() 
    {
        if (Player1 == true )
        {
            checkClickedX();
        }
        else if (Player1 == false)
        {
            checkClickedO();
        }
    }    

    public void checkClickedX()
    {  
        if (Greenfoot.mouseClicked(this))
        {
            Board b = (Board) getWorld();
            b.addObject(new X(), getX(), getY());
            changePlayerToO();
            getWorld().removeObject(this);
        }
    }

    public void checkClickedO()
    {  
        if (Greenfoot.mouseClicked(this))
        {
            Board b = (Board) getWorld();
            b.addObject(new O(), getX(), getY());
            changePlayerToX();
            getWorld().removeObject(this);
        }
    }

    public void changePlayerToO()
    {
        Player1=!Player1;
    }

    public void changePlayerToX()
    {
        Player1=!Player1;
    }
}