BBcode Greasemonkey Multiline tags

I have a greasemonkey script that replaces BBcode with HTML because the admin of a site I frequent won't implement text effects. The problem is when users use tags with multiple lines in them they don't work.

For example:

text text text

Shows as bold text, but


text
text
text


Does not bold the text and the tags stay visible.


Here is the full script. Any ideas on how to make multiple lines work?

http://snipt.org/kkml

mainly just want to get the quote tag working, that's the one they use the most and mess up on by adding multiple lines.

You really need to learn how to write better code. I recommend Factor.