Regular expression to validate and formate text strings.
             PATTERNS/OPERATORS/SYMBOLS

===============================================
       Regular expressions / Special characters :
===============================================
/  (slash) : always begins and ends a regular expression.
\ : toggle between literal and special characters.
^ (caret) : beginning  of the string.
$ : end of the string.
( ) (parenthesis) : reference to a group.
* zero or more time
? zero or one time 
+ one or more time
------------------------------------------------------
\b  : word boundary.
\B  : non-word boundary.
\d  : digits (0->9).
\D  : any non-digits.
\f  : form feed.
\n  : new line.
\.  : any character except new line.
\r  : carriage return.
\s : any white space character.
\S : any non-white space character.
\t  : tabulation.
\v  : vertical tabulation.
\w  : any character (letter, number, underscore).
\W  : any character other than a letter, a number, an underscore.
\xnn  : the ASCII character defined by the hexadecimal nn.
\onn  : the ASCII character defined by the octal nn.
\cX  : the control character X.
------------------------------------------------------
{x} : x occurences of the previous character.
{x,} : at least x occurences of the previous character.
{x,y} : between x and y occurences of the previous character.
{x|y} : x or y occurences of the previous character.
------------------------------------------------------
[ xyz] (bracket) : enclosed characters are allowed;
[^xyz ] : enclosed characters are not allowed;
[ a-k] : any character in this range is allowed;
===============================================                     
               Regular expression Modifier :
                  (set after the final slash)
===============================================
g : search globally for all possible matches.
i : search without case sensitive (lowercase/uppercase).

===============================================                     
               Regular expressions :
                  (samples...)
===============================================
E-mail address :
/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/   
ex : gilles.saunier@free.fr 
------------------------------------------------------
URL :
data = /^(file|http):\/\/\S+\/\S+$/i
ex : http://gilles.saunier.free.fr
------------------------------------------------------
Filename URL :
data = /^(file|http):\/\/\S+\/\S+\.(gif|jpeg|jpg)$/i 
ex : http://gilles.saunier.free.fr/gif/pix.gif
------------------------------------------------------
Phone number :
data = /^\(?(\d{2})\)?[- ]?(\d{4})[- ]?(\d{4})$/
ex : (02) 9863 2884
       02-9863-2884
       0298632884...
------------------------------------------------------
Date :
data = /^(\d{2})[/](\d{2})[/](\d{4})$/
ex : 08/25/2004
------------------------------------------------------
Time :
data = /^(\d{2})[:](\d{2})[:](\d{2})$/
ex : 04:12:56