anchor.diff:    (:documentation "Represents an instance of a lesson, mostly for when a
                      lesson is given to parts of a class separately"))
   
  -(defmacro request-url (url &rest params)
  -  "Requests the URL using drakma, automatically supplying the cookie jar"
  -  `(drakma:http-request ,url
  -                        ,@params
  -                        :cookie-jar *cookie-jar*))
  -
   (defun timestamp->datestring (timestamp)
     "Converts a timestamp to a `datestring`"
     (local-time:format-timestring NIL timestamp :format '((:year 4) (:month 2) (:day 2))))
  
positive.code: (pushnew '("text" . "html") drakma:*text-content-types*)
  
  (defvar *classes*)
  (defparameter *cookie-jar*
    (make-instance 'drakma:cookie-jar
                   :cookies (list
  			   (make-instance 'drakma:cookie
  					  :name "schoolname"
  					  :value "\"_V2luZGVzaGVpbQ==\""
  					  :domain "roosters.windesheim.nl"))))
  
  (local-time:define-timezone 
      amsterdam 
  
negative.code:   "Returns the schedule of the class with the supplied id at the specified
     date. If no date is specified the server will use the current date"
    (caramel:html-resource
     (drakma:http-request (raw-url id date))))
  
  (defun class-id (name)
    "Returns the id associated with the class name. Also returns as a second
  