compiling server prog says interface not needed

[sanjays samadder]

please help with this
I have compiled a .idl file which has given 5 .java files as expected.
but the books say one of them should be HelloImplBase.java
whereas I get one called HelloOperations.java
intitutively I have extended my helloservant class to the HelloOperation class
but the error is:
\helloServant.java:12: no interface expected here
public class helloServant extends HelloOperations
consequently my helloserver calss do not recognize the objects of the helloservant class.
what is happening???
the rest of the codes in different classes I understood
import Hello.*;
import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
public class helloServant extends HelloOperations
{
public String sayHello()
{
return"hello";
}
}

thank you