About JavaMail;

Please have a look in the snippet of this code

I am just trying to get a number of messages in a folder.


import javax.mail.*;
import java.io.*;
import java.net.*;
import java.util.*;

class first{
      public static void main(String[] args) throws MessagingException{
                  URLName urln = new URLName("164.164.61.24");
                  Properties pros = System.getProperties();
                  Session session = Session.getDefaultInstance(pros, null);
                  Store store = session.getStore();
                  store.connect();
                  Folder f = store.getDefaultFolder();
                  System.out.println("The count is " + f.getMessageCount());
      }
}

It is compiling perfectly but when it comes to runtime it is giving me this error

C:\jdk1.2\bin\java.exe   first
Working Directory - C:\javamail\testing\
Class Path - c:\jdk1.2\lib\;c:\jsdk2.1\servlet.jar;c:\jsdk2.1\server.jar;c:\javamail\javamail-1.1.2\mail.jar;.;C:\kawa321\kawaclasses.zip;c:\jdk1.2\lib\tools.jar;c:\jdk1.2\jre\lib\rt.jar
javax.mail.NoSuchProviderException: Invalid protocol: null
      at javax.mail.Session.getProvider(Session.java:208)
      at javax.mail.Session.getStore(Session.java:306)
      at javax.mail.Session.getStore(Session.java:286)
      at javax.mail.Session.getStore(Session.java:272)
      at first.main(first.java:11)
Exception in thread "main" Process Exit...

Pleaes help me to solve this error