Erro na execução

C:\Program Files\Java\jdk1.6.0_16\bin>java multiserver

Exception in thread “main” java.lang.NoClassDefFoundError: manipuladorThread

Caused by: java.lang.ClassNotFoundException: manipuladorThread

at java.net.URLClassLoader$1.run(URLClassLoader.java:200)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:188)

at java.lang.ClassLoader.loadClass(ClassLoader.java:307)

at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)

at java.lang.ClassLoader.loadClass(ClassLoader.java:252)

at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)

Could not find the main class: multiserver.  Program will exit.

O programa é o seguinte

========multiserver.java=========

import <a href="http://java.io">java.io</a>.<em>;

import <a href="http://java.net">java.net</a>.</em>;

//* Classe da thread

class manipuladorThread extends Thread

{

//* conexao usada para conexao concorrente do cliente

Socket newsock;

//* numero da conexao concorrente do cliente

int n;

manipuladorThread(Socket s, int v)
{
    newsock = s;
    n = v;
}

public void run ()
{
    try
      {
        DataInputStream inp = new DataInputStream(newsock.getInputStream());
        PrintStream outp = new PrintStream (newsock.getOutputStream());

        outp.println("Hello :: enter QUIT to exit");

        boolean more_data = true;
        while (more_data)
        {
            String line = inp.readLine();
            if (line==null) more_data=false;
            else
            {
                outp.println("From server: "+line+"\n");
                if (line.trim() . equals("QUIT"))
                    more_data=false;
            }
        }
        newsock.close();
      }
    catch (IOException e)
    {
        System.out.println("IO ERROR "+e);
    }
}

//* Classe principal

class multiserver

{

public static void main(String args[])

{

//* numero da thread concorrente do usuario
    int nreq = 1;

    try
    {
        ServerSocket sock = new ServerSocket(7500);
        for (;;)
        {
            Socket newsock = sock.accept();
            System.out.println("Creating Thread...");
            Thread t = new manipuladorThread(newsock, nreq);
            t.start();
            nreq++;
        }

    }
    catch (IOException e)
    {
        System.out.println("IO ERROR "+e);
    }

}