but I would have it also to make the url of my profile presentation static.
Please stop linkin Scriptfiles
DIRECTLY WITHOUT description
/screenshot/link-to-description. Anybody won't add/install a script without knowing what it does only to see what you mean.
And we still don't know what you mean with "static profilepresentation" you give us a link to a "background.js" file, what have this todo with static URL?! If you want to have a special Background: check out the Background Feature from BBLog. If not, describe your request in words, not with links to scripts.