This post follows my previous post.  I am struggling to write to a
hashtable.  I have included more code this time. See below:

public void handleAddPlane()
   {

       String planeRegisNum = "";
       String planeModel = "";
       System.out.println("User wants to add a plane");

       System.out.println("Please enter plane registation number: ");
       planeRegisNum = readKeyboard().toUpperCase();
       while(planeRegisNum.equals("")){
            System.out.println("Wrong entry: ");
       }
       System.out.println("Please enter plane model number: ");
       planeModel = readKeyboard().toUpperCase();
       while(planeModel.equals("")){
            System.out.println("Wrong entry: ");
       }
       Block b[] = seatBlocks(planeModel);

       AirPlane plane = new AirPlane(b, planeRegisNum, planeModel);
       if (!airPlanes.containsKey(planeRegisNum))
       {
           try {
            airPlanes.put(planeRegisNum, plane);
           }
           catch(Exception ex){
               System.out.println("Problem Adding a Plane to a hash
table");
           }

          System.out.println("Airplane was successfully added");
       }

 }

Thanks tuurbo