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

public class Object extends Actor
{
    public void act() 
    {
        MouseInfo pointer = Greenfoot.getMouseInfo();
        if(pointer != null)
        {
            int mouseX = pointer.getX();
            int mouseY = pointer.getY();
            turnTowards(mouseX, mouseY);
            int button = pointer.getButton();
            if(button == 1)
            {
                move(20);
            }
        }
    }    
}