cannot resolve symbol

This the error description:

C:\Program Files\Apache Software Foundation\Tomcat 5.0\webapps\begjsp-ch07\WEB-I
NF\classes\com\wrox\library>javac ChildrenBook.java
ChildrenBook.java:3: cannot resolve symbol
symbol  : class BookNew
location: class com.wrox.library.ChildrenBook
public class ChildrenBook extends BookNew {
                                  ^
1 error
==========
These are the classes:

package com.wrox.library;

public class ChildrenBook extends BookNew {

      private int minmumAge;
      
      public int getMinmumAge() {
            return minmumAge;
      }
      
      public void setMinmumAge(int a) {
            minmumAge = a;
      }
      
      public ChildrenBook() {
            super();
      }
      
      public ChildrenBook(String title) {
            super(title);
      }      
}

===============
package com.wrox.library;

public class BookNew {

      private String title;
      
      public String getTitle() {
            return title;
      }
      
      public void setTitle(String title) {
            this.title = title;
      }
      
      public BookNew() {
      }
      
      public BookNew(String title) {
            this.title= title;
      }      
}

Question: What is wrong? How can I correct the problem I am having?

When I combine public class ChildrenBook and class Book in the same file it works okay. Basicallt it comes down to how I need to change the first line in my CheldrenBook class so it can find Book class. Do I need to revise PATH string somewhere?

package com.wrox.library;


I will try this in for now until someone could figue out what is happening here. Also I am reading about tag libraries and tag handlers in case the problem may is related.

Thank you.