[TYPO3] Realurl , wrong urls and menu links

[Tomas Larsen]

1) Is there a way to not show the Typo3 Error! Page when a bad link is
entered? - instead I would like to show a specific page id=12 for my own
error message.

I get the following error:
Reason: Segment "nonexistent_page" was not a keyword for a postVarSet as
expected!

2) Also how to i change the menu so it uses domain.tld/page/name/something
instead of index.php?id=123

Regards
Tomas Larsen
Jmedia.dk