If you want to practice with regexes consider using, if on windows,
a coach or
Davido's precious regex tester that
is now here also
onther testing site suggested by
Eily also, anonimously suggested,
rxrx and
this one and
this other one and also
VRegExp
HtH
L*
There are no rules, there are no thumbs..
Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.