RE: If arg, open in new frame

[torys.anderson@gmail.com (Tory S. Anderson)]

So, that half answered my question: thanks for showing me how to use optional args. My function is now:

(defun go-or-make-agenda (&optional new-frame) (interactive "P")
  (let ((buffer "\*Org Agenda\*"))
    (if (get-buffer buffer)
	(switch-to-buffer buffer)
      (org-agenda-list))))

But I actually don't know how to open this in a new frame. I guess I should have given my more specific use case:

I use this function to check my calendar. Sometimes, I want to do that without losing what I have open right now (especially when I'm reading an email in Gnus that asks me about an appointment). Right now I have to respond with, `C-x 5 2 M-x go-or-make-agenda` (the function actually being bound to <F8>). I'd like to shorten this effort to just doing `C-u <F8>`. Google is not readily serving me for how to open in another frame in elisp. 

>Date: Wed, 10 Sep 2014 00:44:20 +0200
>From: Emanuel Berg <embe8573@student.uu.se>
>torys.anderson@gmail.com (Tory S. Anderson) writes:
>
>> I have a function that checks for a buffer and either
>> switches to it or creates it. I want it to optionally
>> take an arg, and if an arg is supplied, open/find
>> said buffer in a new frame. My elisp-fu is still
>> young; can you help?
>>
>> Function:
>>
>> (defun go-or-make-agenda () (interactive)
>>   (if (get-buffer "\*Org Agenda\*")
>>       (switch-to-buffer "\*Org Agenda\*")
>>     (org-agenda-list)))
>
>Hint: As the data "\*Org Agenda\*" appears twice, put
>that in a `let' and have it appear once, then use the
>`let' binding all you want.
>
>As for your question, I think you can solve the frame
>stuff (I didn't exactly understand your motive but it
>doesn't matter), but take a look below for an optional
>(prefix) argument. Then just put it together.
>
>(defun go-or-make-agenda (&optional new-frame)
>  (interactive "P")
>  (if new-frame (message "frame")
>    (message "no frame") ))
>
>;; from Elisp
>(go-or-make-agenda)       ; no frame
>(go-or-make-agenda nil)   ; no frame
>(go-or-make-agenda t)     ; frame
>
>;; interactively
>M-x go-or-make-agenda RET     ; no frame
>C-u M-x go-or-make-agenda RET ; frame
>
>-- 
>underground experts united
>