(define-class (student name)
  (instance-vars (employer 'None))        ;;NEW
  (method (greet)
	  (print (list 'hi 'i 'am name)))
  (method (change-name new-name)
	  (set! name new-name))
  (method (find-job new-boss)           ;;NEW
	  (set! employer new-boss))      ;;NEW
  (method (co-workers-greet)                    ;;NEW
	  (for-each (lambda (p)                 ;; NEW
		      (if (not (eq? p self))     ;; NEW
			  (ask p 'greet)))          ;; NEW
		    (ask employer 'employees))))   ;; NEW


(define min (instantiate student 'minxu))
(define chris (instantiate student 'chrislin))
(define charles (instantiate student 'charleschen)) 


;;;; in-n-out class defn ;;;;;;;;

(define-class (in-n-out location)
  (instance-vars (employees '()))
  (method (hire student)
	  (set! employees (cons student employees))
	  (ask student 'find-job self))               ;; NEW
  (method (all-greet)
	  (for-each (lambda (p) (ask p 'greet)) employees)))

	   
(define in1 (instantiate in-n-out 'pinole))
(define in2 (instantiate in-n-out 'fremont))