Open file types with emacs-w3m

[harry meyers <latelate@xxxxxxxxxxxxxxxxxxxxx>]

Hello,

I use emacs-w3m (especially w3m-namazu), but I do not succeed to open files with
external viewers. For dired I have extview.el installed which apparently has no
influence on emacs-w3m.
So I tried to customize emacs-w3m via w3m Content Type Alist, that means I
specified xpdf for a pdf viewer, which does not work. 
Something like that

(setq w3m-content-type-alist
('("application/postscript" "\\.e?ps\\'" ("gv" file) nil)
          ("application/pdf" "\\.pdf\\'" ("xpdf" file) nil)))

does not work either. What else can I do?

harry