interface again

[Neha Sawant]

this code is complaining that Observer interface not found in class B1.
what is my mistake here.
Anyone please
class A implements Runnable{
public void run(){}}
class B1 extends A implements Observer {
public static void main(String args[]){
A a = new A() ;
B1 b = new B1();
Object o=a; Runnable r = o;
Object o=a; Runnable r = (Runnable)o;
//Object o=a; Observer ob = (Observer)o;
Object o=b; Observer o2 = o;
Object o=b; Runnable r = (Runnable)b;
Object o=b; Observer o2 =(Observer)o;
Observer o=new B();
}

[Michael Ernest]

Did you import the package they're in (java.util)?
------------------
Michael Ernest, co-author of: The Complete Java 2 Certification Study Guide

[Fei Ng]

import java.util.*;
do you have that?

[Neha Sawant]

thanx Micheal And FEING
That was my mistake.
Will we be tested on these also.
i.e. do we have to point out whether import statement is missing
_Neha