(Help) Understanding the folding-mode

[Anne Kaeppes]

I like the emacs, but the folding-mode: I don't understand...

I have installed folding.el, it works...

I have added to my .emacs to

(load "folding" 'nomessage 'noerror)
(folding-mode-add-find-file-hook)
(folding-add-to-marks-list 'php-mode                "//{"  "//}"  nil t)
(folding-add-to-marks-list 'prolog-mode             "%{{{" "%}}}" nil t)
(folding-add-to-marks-list 'html-mode               "<!-- {{{ " "<!-- 
}}} -->" " -->" nil t)
(folding-add-to-marks-list 'latex-mode               "%{{{"  "%}}}" nil t)
(folding-add-to-marks-list 'javascript-mode          "//{"  "//}" nil t)
(folding-add-to-marks-list 'java-mode                "//{"  "//}" nil t)
(folding-add-to-marks-list 'c-mode                "//{"  "//}" nil t)

But it all don't works. Only in the latex-mode I can change mit ESC-X 
folding-mode (hide or show all)

The key combination C-u 2 C-x $ (horrible combination) doesn't work, 
always reporting me a "selective-display already in use for marked lines"


I don't understand the .emacs file exactly, but i didn't notive any 
errors in the *Message* buffer..

So, how can I bring the folding-mode to work, and, more important,
how can I change the key-combination to somethink others like function 
keys...

I use the EMacs Version 21.3.

Thanks for help
regards
Anne