[Mozile] INFORMATION ABOUT MOZILE -moz-user-modify

[Luca Cervone]

Hi,
I'm  a student of computer science at the university of bologna(Italy).
For my thesis i'm working on a WYSIWYG editor and i need a fragment of
mozile's code.
But there is something that i don't understend.

For example:
Suppose I have a node whit the -moz-user-modify attribute.
What is the mechanism that make the aforesaid node accepts the input of
the user?
In particular what is the fragment of code that do it?

Sorry for my english...
Thanks for any answer.

Luca Cervone