if you want to quickly test your regular expressions, here is a free online-tool called RegExr
that i find extremely helpful:http://gskinner.com/RegExr/
You can simply enter some text, write a regex and this tool then highlights all matches in your text.
It also has "before and after" preview feature for search and replace regex-actions.
If you want an offline version of this tool, you can also download "desktop version" (the link is at the bottom right).http://gskinner.com/RegExr/
(you'll need adobe's AIR to run the tool http://get.adobe.com/de/air/