[Mediawiki-l] Language text changed, link to other languages

[WikiPlant]

hi, I have two new quetions: I changed the text in the text for the 
image upload in the file Language_de.php and uploaded it, but I can't 
see the changes on the page Spezial:Upload... I deleted all cookies and 
the cache but nothing did happen :(
the other question is: My wiki is on de.domain... I have another wiki on 
en.domain.. how can I link between those sites? I tried it with 
[[en:]]... that failed. Thanks for helping me :)
Florian