function CheckLN()
{
   var oldea = document.regform.oldea.value;
   var oldpw = document.regform.oldpw.value;
   var newea = document.regform.newea.value;
   var newea2 = document.regform.newea2.value;
   var newpw = document.regform.newpw.value;
   var newpw2 = document.regform.newpw2.value;
   var pwsame = document.regform.pwsame;
   var prsame = document.regform.prsame;
   var pwr    = document.regform.pwr.value;
   var newea_chk = newea.match(newea2);
   var newpw_chk = newpw.match(newpw2);
   var msg = '';
   var emailmsg = '';


   if (!document.regform.agree.checked) {
      msg += "You must explicitly agree to the Terms of Use by checking the box where indicated.\n";
   } 

   if (!oldea) {
     msg += "Your old email address is missing.\n";
   } else {
	emailMsg = check_email(oldea,1);
        msg = msg + emailMsg;
   }

   if (!oldpw) {
     msg += "Your old password is missing.\n";
   }

   if (!newea) {
     msg += "Your new email address is missing.\n";
   } else {
	emailMsg = check_email(newea,2);
        msg = msg + emailMsg;
   }

   if (!newea2) {
     msg += "Your new email address confirmation is missing.\n";
   } else {
	emailMsg = check_email(newea,2);
        msg = msg + emailMsg;
   }

        // Determine which item from the array was clicked:        
    for (x=0; x < pwsame.length; x++){        
	if ((pwsame[x].checked) && (pwsame[x].value == "n"))  {
		if (newpw.length<1)  {
			msg += "You must provide a new password if not keeping the old one.\n";
   		} else {
   			if ((newpw2.length<1) || (newpw_chk==null))  {
				msg += "Your new password must be identical where its entered twice.\n";
   			}
   		}
   	}
   }


    for (x=0; x < prsame.length; x++){        
	if ((prsame[x].checked) && (prsame[x].value == "n") && (pwr.length<1))  {
		msg += "You must provide a new hint if not keeping the old one.\n";
   	}
   }


/* using this method to check for identical values will not act unless there is
   a non-null value in both fields.  */

   if (newea_chk==null)  {
	msg += "Your new email address must be identical where its entered twice.\n";
   }


   if (msg.length > 0)  {
	alert(msg);
	return false;
   }


   return true;
}


function check_email(emailAddr,typ) {

var src = "old ";
if (typ==2) { src = "new "; }

/* 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. */

var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;

/* 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. */

/* First, change input to lower case, else we may fail domain check - LSB */
emailAddr=emailAddr.toLowerCase()  

var matchArray=emailAddr.match(emailPat);

if (matchArray==null) {

/* Too many/few @'s or something; basically, this address doesn't
even fit the general mold of a valid e-mail address. */

	return("Your " + src + "email address seems incorrect (check @ and .'s)\n");

} 

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("The username in your " + src + "email address contains invalid characters.\n");
}

for (i=0; i<domain.length; i++) {
  if (domain.charCodeAt(i)>127) {
	return("The domain name in your " + src + "email address contains invalid characters.\n");
  }
}

// See if "user" is valid 

if (user.match(userPat)==null) {
	return("The username in your " + src + "email address doesn't seem to be valid.\n");
}

/* 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) {
		return("The IP address portion of your " + src + "email address is invalid!\n");
   	  }
	}
}

// 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("The domain name in your " + src + "email address does not seem to be valid.\n");
  }
}

/* domain name seems valid, but now make sure that it ends in a
known top-level domain (like com, edu, gov) or a two-letter word,
representing country (uk, nl), and that there's a hostname preceding 
the domain or country. */

if (checkTLD && domArr[domArr.length-1].length!=2 && 
domArr[domArr.length-1].search(knownDomsPat)==-1) {
	return("Your " + src + "email address must end in a well-known domain or two letter " + "country.\n");
}

// Make sure there's a host name preceding the domain.

if (len<2) {
  return("Your " + src + "email address is missing a hostname!\n");
}

return "";
}
}