Cannot find symbol

[SarahB]

Hello,

I have a problem when compiling my program on "cmd", i receive the error "cannot find symbol"

Here's my code :

package StrategyPattern;

/**
 *
 * @author Sarah
 */
public interface Quackable
{
    public void makeSound();

}

package StrategyPattern;

/**
 *
 * @author Sarah
 */
public interface Flyable
{
    public void fly();

}

package StrategyPattern;

/**
 *
 * @author Sarah
 */
public abstract class Duck
{
    Quackable quack;
    Flyable fly;
    String name;
    public abstract void display();

    public void setSound(Quackable quack)
    {
        this.quack=quack;
    }
    public void setFly(Flyable fly)
    {
        this.fly=fly;
    }

    public void makeSound()
    {
        quack.makeSound();
    }

    public void fly()
    {
        fly.fly();
    }


}

The classes Quackable and Flyable compile fine, but i get the error when I try to compile the Duck class. The program is working fine on NetBeans.

Here's one of the errors when compiling the Duck class:

Duck.java: 14: cannot find symbol
symbol: class Quackable
location: class StrategyPattern.Duck
Quackable Quack

The rest of the errors are similar to this one but it says cannot find symbol "Flyable fly" .

Thanks in advance.