var agt = navigator.userAgent.toLowerCase();
	is_major = parseInt(navigator.appVersion);
	is_minor = parseFloat(navigator.appVersion);
	is_ie  = ((agt.indexOf("msie") != -1) && (agt.lastIndexOf(")") == agt.length-1));
	is_ie5  = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")!=-1) );
	is_ie5up = (is_ie && (is_major == 4) && (agt.indexOf("msie 4.0")==-1) );
	is_nav = (navigator.appName.indexOf("Netscape") != -1);
	is_win = ( (agt.indexOf("win")!=-1) || (agt.indexOf("16bit")!=-1) );
	is_mac = (agt.indexOf("mac")!=-1);
	is_nav4 = (is_nav && is_major == 4);
	is_nav6 = (is_nav && (is_major > 4));

	var is_ie4 = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.")==-1) && (agt.indexOf("msie 6.")==-1) );
	var is_ie4_5 = (is_ie && (agt.indexOf("msie 4.5")!=-1) );
	var is_aol = (agt.indexOf("aol") != -1);

	var is_win95 = ((agt.indexOf("win95")!=-1) || (agt.indexOf("windows 95")!=-1));
	var is_win98 = ((agt.indexOf("win98")!=-1) || (agt.indexOf("windows 98")!=-1));
	var is_winnt = ((agt.indexOf("winnt")!=-1) || (agt.indexOf("windows nt")!=-1));
	var is_win32 = (is_win95 || is_winnt || is_win98 ||
					((is_major >= 4) && (navigator.platform == "Win32")) ||
					(agt.indexOf("win32")!=-1) || (agt.indexOf("32bit")!=-1));
	var is_osx = (is_mac && ((agt.indexOf("mac os x")!=-1) || (is_ie5up && !((agt.indexOf("msie 5.0")!=-1) || (agt.indexOf("msie 5.13")!=-1)))) );


function ltrim(s) {
   var count=0;
   var i = 0;
   var space = " ";
   var newLine="\n";
   var cr = "\r";
   var tab = "\t";
   var sRet = s;
   while (
      (s.charAt(i) == space) ||
      (s.charAt(i) == newLine) ||
      (s.charAt(i) == cr) ||
      (s.charAt(i) == tab)){
      count++;
      i++
    }
   if (count > 0)
      sRet = s.substring(count, s.length);

   return(sRet);
}

function rtrim(s) {
   var count=0;
   var i = s.length - 1;
   var space = " ";
   var newLine="\n";
   var cr = "\r";
   var tab = "\t";
   var sRet = s;

   while (
      (s.charAt(i) == space) |
      (s.charAt(i) == newLine) |
      (s.charAt(i) == cr) |
      (s.charAt(i) == tab)) {
      count++;
      i--
   }
   if (count > 0)
      sRet = s.substring(0, s.length - count);

   return(sRet);
}


function trim(s) {
   return(rtrim(ltrim(s)));
}

function isNum(s){
	if ((s>="0") & (s<="9"))
	 { return true }
	else
	 { return false }
}

function isNumaric(s) {
	var i = 0;
	var count=0;
	var sRet = s;
	var prdcnt = 0;


	if (s.length == 0) {return true}
	while( (isNum(s.charAt(i)) | s.charAt(i) == ".") & (s.length >= i) )
	{
	   if (s.charAt(i) == ".")
		  { prdcnt = prdcnt+1; }

	   i++;
	}

	if (prdcnt >1) { return true }

	if (s.length == i ) {return false}
	return true
}


function isEmail (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. */

	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. */

	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 address seems incorrect (check @ and .'s)");
		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) {
			alert("Ths username contains invalid characters.");
			return false;
		   }
		}
		for (i=0; i<domain.length; i++) {
			if (domain.charCodeAt(i)>127) {
			alert("Ths domain name contains invalid characters.");
			return false;
		   }
	}

	// See if "user" is valid

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

		// user is not valid

		alert("The username doesn't seem to be valid.");
		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("Destination IP address is invalid!");
				return false;
			   }
		}
		return true;
	}

	// 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) {
			alert("The domain name does not seem to be valid.");
			return false;
		   }
	}

	/* 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) {
		alert("The address must end in a well-known domain or two letter " + "country.");
		return false;
	}

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

	if (len<2) {
		alert("This address is missing a hostname!");
		return false;
	}

	// If we've gotten this far, everything's valid!
	return true;
}