If you are someone like me, you find Regular expressions to be a pain to wright, due to their arcane syntax.  It might as well as be Greek based up the amount of time I spend pondering each character in the expression. Which is why it's usually much more convenient to look up from the internet, which is why I'm placing a link to the Regular Expression Library. This site has hundreds of regular expression for your everyday validation needs, from phone numbers to Urls to html tags to email addresses.

Now if the above library doesn't work or you feel that you're manly enough to conjure your own expressions, you can use This javascript based test site to help with the incatnations.