[Mediawiki-l] Log in / create account changing

[Oliver Schalch]

Hi List,

I'd like to change the Login / create account Site:
wiki/index.php?title=Special:Userlogin&type=signup

Which files I have to edit, and probleme where I could add some PHP
scripting.

I want something like this (red text):
http://i7.tinypic.com/33f7ud1.png

And probably if its not that hard - a little script which checks the
username form if there are 3 letters.
Scripting i do byself but I'm not sure where to put ;-)

TIA for any hints.
Oliver