Possible to access previous arg in `interactice' call?

[Thorsten Jolitz]

Hi List, 

in this example, is there a way to access num1 while reading num2?

#+begin_src emacs-lisp
  (defun foo (num1 num2)
   (interactive
      (list
         (read-number "Num1: ")
         (+ (read-number "Num2: ") num1)))
   (message "num1: %s\nnum2: %s" num1 num2))
#+end_src

#+results:
: foo

#+begin_src emacs-lisp
 (call-interactively 'foo)
#+end_src

-> list: Symbol's value as variable is void: num1

-- 
cheers,
Thorsten