Setting default browser for "export b" on Win7

Setting default browser for "export b" on Win7

[mirko]

I am trying to set Firefox as the default browser on my Windows 7 machine.

Here is the elisp code that modifies org-file-apps

(defun mv-org-set-export-browser (browser)
  (setq org-file-apps
	(mapcar (lambda (entry)
		  (if (string= (car entry) "\\.x?html?\\'")
		      (cons (car entry)
			    (if (equal browser 'default)
				browser
				(format "%s %s" browser "%s")))
		      entry))
		org-file-apps)))


I call it like this:

(mv-org-set-export-browser 'default
			   ;;"firefox"
			   ;;"c:/Program Files (x86)/Mozilla Firefox/firefox.exe"
)

The two commented lines are when I try to set firefox as the browser.  But
with either of them, I get no visible output.  I don't see anything in
*Messages*.  (Thus the 'default is uncommented).

I know the full path to work, as it is the same string that is used to
specify the default browser for opening URL's.

Any ideas on what is going wrong?

Thanks,

Mirko