I’m no expert with regular expression and while googling, I came across this very useful tool that helps to do live matching of regular expressions. Its built in Flex 
If you are scratching your head over those pesky characters that come from Mars, check out:
http://www.idsklijnsma.nl/regexps/
I just came across your site and your article on the regular expression tester for Flash/Flex. I recently created a similar tool and thought you might be interested in it.
The app is called the Flex 3 Regular Expression Explorer and can be found at my blog below.
http://blog.ryanswanson.com/2008/10/introducing-flex-3-regular-expression.html
The application is similar to the Flex Component and Style Explorers created by Adobe, but I have also added a collaborative community section where people can post their own regular expression examples as well as a full-feature help panel to get novices started with the technology.
Hope you like it!
Cheers,
Ryan
Hey thanks ryan for sharing what you created. I think it is awesome, great work there
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