<SCRIPT LANGUAGE="Javascript">
<!-- Changes: Sandeep V. Tamhankar (stamhankar@hotmail.com) -->
/* 1.1.2: Fixed a bug where trailing . in e-mail address was passing
(the bug is actually in the weak regexp engine of the browser; I
simplified the regexps to make it work).
1.1.1: Removed restriction that countries must be preceded by a domain,
so abc@host.uk is now legal. However, there's still the
restriction that an address must end in a two or three letter
word.
1.1: Rewrote most of the function to conform more closely to RFC 822.
1.0: Original */
<!-- This script and many more are available free online at -->
<!-- The JavaScript Source!! http://javascript.internet.com -->
<!-- Begin
function emailCheck (emailStr) {
/* The following pattern is used to check if the entered e-mail address
fits the user@domain format. It also is used to separate the username
from the domain. */
var emailPat=/^(.+)@(.+)$/
/* The following string represents the pattern for matching all special
characters. We don't want to allow special characters in the address.
These characters include ( ) < > @ , ; : \ " . [ ] */
var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]"
/* The following string represents the range of characters allowed in a
username or domainname. It really states which chars aren't allowed. */
var validChars="\[^\\s" + specialChars + "\]"
/* The following pattern applies if the "user" is a quoted string (in
which case, there are no rules about which characters are allowed
and which aren't; anything goes). E.g. "jiminy cricket"@disney.com
is a legal e-mail address. */
var quotedUser="(\"[^\"]*\")"
/* The following pattern applies for domains that are IP addresses,
rather than symbolic names. E.g. joe@[123.124.233.4] is a legal
e-mail address. NOTE: The square brackets are required. */
var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/
/* The following string represents an atom (basically a series of
non-special characters.) */
var atom=validChars + '+'
/* The following string represents one word in the typical username.
For example, in john.doe@somewhere.com, john and doe are words.
Basically, a word is either an atom or quoted string. */
var word="(" + atom + "|" + quotedUser + ")"
// The following pattern describes the structure of the user
var userPat=new RegExp("^" + word + "(\\." + word + ")*$")
/* The following pattern describes the structure of a normal symbolic
domain, as opposed to ipDomainPat, shown above. */
var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$")
/* Finally, let's start trying to figure out if the supplied address is
valid. */
/* Begin with the coarse pattern to simply break up user@domain into
different pieces that are easy to analyze. */
var matchArray=emailStr.match(emailPat)
if (matchArray==null) {
/* Too many/few @'s or something; basically, this address doesn't
even fit the general mould of a valid e-mail address. */
alert("Email адрес введен некорректно (проверьте @ и .'s)")
return false
}
var user=matchArray[1]
var domain=matchArray[2]
// See if "user" is valid
if (user.match(userPat)==null) {
// user is not valid
alert("Имя пользователя введено неверно или отсутствует.")
return false
}
/* if the e-mail address is at an IP address (as opposed to a symbolic
host name) make sure the IP address is valid. */
var IPArray=domain.match(ipDomainPat)
if (IPArray!=null) {
// this is an IP address
for (var i=1;i<=4;i++) {
if (IPArray[i]>255) {
alert("IP адрес назначени неверный или отсутствует!")
return false
}
}
return true
}
// Domain is symbolic name
var domainArray=domain.match(domainPat)
if (domainArray==null) {
alert("Неверно введено или отсутствует имя домена.")
return false
}
/* domain name seems valid, but now make sure that it ends in a
three-letter word (like com, edu, gov) or a two-letter word,
representing country (uk, nl), and that there's a hostname preceding
the domain or country. */
/* Now we need to break up the domain to get a count of how many atoms
it consists of. */
var atomPat=new RegExp(atom,"g")
var domArr=domain.match(atomPat)
var len=domArr.length
if (domArr[domArr.length-1].length<2 ||
domArr[domArr.length-1].length>3) {
// the address must end in a two letter or three letter word.
alert("Адрес должен заканчиваться 3 буквами после точки для домена, или 2 буквами для страны.")
return false
}
// Make sure there's a host name preceding the domain.
if (len<2) {
var errStr="У адреса пропущено или отсутствует имя хостинга!"
alert(errStr)
return false
}
// If we've gotten this far, everything's valid!
return true;
}
// End -->
</script>
|