function emailCheck (emailStr) {
/* The following variable tells the rest of the function whether or not
to verify that the address ends in a two-letter country or well-known
TLD.  1 means check it, 0 means don't. */
var checkTLD=1;

/* The following is the list of known TLDs that an e-mail address must end with. */
// Modified by Rohit ( 24-DEC-2007). Added the i flag at the end
// to make the regular expression case insensitive
// so that .goV is also considered a valid email address as also .Gov


var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum|cat|[a-zA-Z][a-zA-Z]|COM|NET|ORG|EDU|INT|MIL|ARPA|BIZ|AERO|NAME|COOP|INFO|PRO|MUSEUM|CAT)$/i;

/* 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 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 + ")";

// The following pattern describes the structure of the user

var userPat=new RegExp("^" + word + "(\\." + word + ")*$" );


/* 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. */

return false;
}
var user=matchArray[1];
var domain=matchArray[2];

// Start by checking that only basic ASCII characters are in the strings (0-127).

for (i=0; i<user.length; i++) {
if (user.charCodeAt(i)>127) {
return false;

   }
}
for (i=0; i<domain.length; i++) {
if (domain.charCodeAt(i)>127) {
return false;
   }
}

// See if "user" is valid

if (user.match(userPat)==null) {

// user is not valid

return false;
}


// Domain is symbolic name.  Check if it's valid.

var atomPat=new RegExp("^" + atom + "$");
var domArr=domain.split(".");
var len=domArr.length;
for (i=0;i<len;i++) {
if (domArr[i].search(atomPat)==-1) {
return false;
   }
}

if (checkTLD && domArr[domArr.length-1].search(knownDomsPat)==-1) {
return false;
}

if (len<2) {
return false;
}

return true;
}