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;
	}

}