This is a my program.

import javabook.*;
class MyFirstApplication
{
public static void main(String args[])
{
MainWindow mainWindow;
mainWindow= new MainWindow();
mainWindow.show();
}
}
When I complie it with message error:
C:\>javac MyFirstApplication.java
MyFirstApplication.java:1: package javabook does not exist
import javabook.*;
^
MyFirstApplication.java:6: cannot resolve symbol
symbol : class MainWindow
location: class MyFirstApplication
MainWindow mainWindow;
^
MyFirstApplication.java:7: cannot resolve symbol
symbol : class MainWindow
location: class MyFirstApplication
mainWindow= new MainWindow();
^
3 errors
Who help me to repair this program. Thanks