JGrasp - No Main Method / Applet Or IMDlet

I have been trying to get this code to work but in jGrasp it give the no main method, applet, or IMDlet. The assignment states: Design a class Message that models an e-mail message. A message has a recipient, a sender, and a message text. Support the following methods:

-A constructor that takes the sender and recipient
-A method append that appends a line of text to the message body a method toString that makes the message into one long string like this:

"From:Harry Morgan
To: Rudolf Reindeer. . ."

Write a program that uses this class to make a message and print it. package emailmodel;

import java.util.Scanner;
public class Message
{
private String senderemail;
private String receiveremail;

[code]....