/**
   This class models a simple letter.
 */
public class Letter
{
   private String from;
   private String to;
   private String text;

   /**
      Constructs a letter with a given sender and recipient.
      @param from the sender
      @param to the recipient
   */
   public Letter(String from, String to)
   {
      this.from = from;
      this.to = to;
      text = "";
   }

   /**
      Adds a line to the body of this letter.
   */
   public void addLine(String line)
   {
      text = text +line + "\n";
   }

   /**
      Gets the text of this letter.
   */
   public String getText()
   {
      String output = "Dear " + to + ":\n\n";
      output += text + "\nSincerely,\n\n" + from + ".";
      return output;
   }
}