Getting "Exception in thread "main" java.lang.NoSuchMethodError: main"?

Question

Possible Duplicate:
Exception in thread “main” java.lang.NoSuchMethodError: main

I am fairly new to Java, and I am unable to figure out why I am getting NoSuchMethodError: main when I execute the following code. I am not sure what does the NoSuchMethodError is pertaining to. It looks like I have everything right. Please help me out here. Thanks a lot.

public class ThreadExample1 extends Thread 
 {
    static String[] msg = {"Java", "programming", "is", "the", "best"};
    public ThreadExample1(String id) 
    {
       super(id);
     }
    @Override
    public void run() 
        {
         try 
           {
             Output.displayList(getName(), msg);
            } 
    catch (InterruptedException ex) 
        {

        }
    }
  }

class Output 
 {
  public static void displayList(String name, String list[]) throws InterruptedException 
   {
     for (int i = 0; i < list.length; i++) 
    {
          Thread.currentThread().sleep((long) (3000 * Math.random()));
          System.out.println(name + list[i]);
         }
    }
   public static void main(String[] args) 
    {
         ThreadExample1 thread1 = new ThreadExample1("thread1: ");
         ThreadExample1 thread2 = new ThreadExample1("thread2: ");
         thread1.start();
         thread2.start();
         boolean t1IsAlive = true;
         boolean t2IsAlive = true;
         do 
          {
          if (t1IsAlive && !thread1.isAlive()) 
            {
              t1IsAlive = false;
              System.out.println("t1 is dead.");
             }
          if (t2IsAlive && !thread2.isAlive()) 
            {
              t2IsAlive = false;
              System.out.println("t2 is dead.");
              }
           }while (t1IsAlive || t2IsAlive);
     }
}

Answer 1

I don't have any problem compiling and executing the above code ... Keep in mind that when you want to execute it , you need to use this command line :

java Output

and NOT :

java ThreadExample1

because the main method is within the Output calss and not in ThreadExample1 ...