Can't figure out what's wrong with Example.java

 public class ForumPost {
  private User mAuthor;
  private String mTitle;
  private String mDescription;

  public User getAuthor() {
    return mAuthor;
  }

  public String getTitle() {
    return mTitle;
  }

  public String getDescription() {
  return mDescription;
  }

     public ForumPost(User author, String title, String description) {

       mAuthor = author;
       mTitle = title;
       mDescription = description;
     }



  // TODO: We need to expose the description
}

public class User {

  private String mFirstName;
  private String mLastName;

  public String getFirstName (){
    return mFirstName;
  }

    public String getLastName (){
    return mLastName;
  }

  public User(String firstName, String lastName) {
    // TODO:  Set the private fields here

    mFirstName = firstName;
    mLastName = lastName;
  }
}

public class Forum {
  private String mTopic;

  public String getTopic() {
      return mTopic;
  }

  public Forum (String newTopic){
  mTopic = newTopic;
  }


  public void addPost(ForumPost post) {


      System.out.printf("New post from %s %s about %s.\n",
                         post.getAuthor().getFirstName(),
                         post.getAuthor().getLastName(),
                         post.getTitle());

  }
}

public class Example {

  public static void main(String[] args) {
    System.out.println("Starting forum example...");
    if (args.length < 2) {
       System.out.println("first and last name are required. eg:  java Example Craig Dennis");
    }
     Forum forum = new Forum("Java");
     //Take the first two elements passed args
     User author = new User(args[0],args[1]);
     //Add the author, title and description
     ForumPost post = new ForumPost(author,title ,description);
     Forum.addPost(post);
  }
}