/*

	Frank Marion, software@frankmarion.com
	http://www.frankmarion.com

	Date Created:	Tuesday, May 31, 2005 06:47 PM
	Last Modified:	Tuesday, May 31, 2005 06:47 PM
	Revision:		1.0

	Function: Validate an email for the "subscribe to email form"

*/

function emailCheck (emailStr) {
	var checkTLD=1;
	var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;
	var emailPat=/^(.+)@(.+)$/;
	var specialChars='\\(\\)><@,;:\\\\\\\"\\.\\[\\]';
	var validChars='\[^\\s' + specialChars + '\]';
	var quotedUser='(\"[^\"]*\")';
	var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
	var atom=validChars + '+';
	var word='(' + atom + '|' + quotedUser + ')';
	var userPat=new RegExp('^' + word + '(\\.' + word + ')*$');
	var domainPat=new RegExp('^' + atom + '(\\.' + atom +')*$');
	var matchArray=emailStr.match(emailPat);
	if (matchArray==null) {
		alert('Email address seems incorrect (check @ and .\'s)');
		return false;
	}
	var user=matchArray[1];
	var domain=matchArray[2];
	for (i=0; i<user.length; i++) {
		if (user.charCodeAt(i)>127) {
			alert('Ths username contains invalid characters.');
			return false;
	   }
	}
	for (i=0; i<domain.length; i++) {
		if (domain.charCodeAt(i)>127) {
			alert('Ths domain name contains invalid characters.');
			return false;
	   }
	}
	if (user.match(userPat)==null) {
		alert('The username doesn\'t seem to be valid.');
		return false;
	}
	var IPArray=domain.match(ipDomainPat);
	if (IPArray!=null) {
		for (var i=1;i<=4;i++) {
			if (IPArray[i]>255) {
				alert('Destination IP address is invalid!');
				return false;
			}
		}
		return true;
	}
	var atomPat=new RegExp('^' + atom + '$');
	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;
		}
	}
	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;
	}
	if (len<2) {
		alert('This address is missing a hostname!');
		return false;
	}
	return true;
}