function emailCheck (emailStr) 
{
	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)$/;

	var emailPat=/^(.+)@(.+)$/;

	var specialChars="\\(\\)><@,;:\\\\\\\"\\.\\[\\]";

	var validChars="\[^\\s" + specialChars + "\]";

	var quotedUser="(\"[^\"]*\")";


	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 + '+';

	var word="(" + atom + "|" + quotedUser + ")";

	// The following pattern describes the structure of the user

	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];

	// 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("In email ID username contains invalid characters.");
			return false;
		}
	}

	for (i=0; i<domain.length; i++)
	{
		if (domain.charCodeAt(i)>127)
		{
			//alert("In email ID domain name contains invalid characters.");
			return false;
		}
	}

	// See if "user" is valid 

	if (user.match(userPat)==null) 
	{								// user is not valid
		//alert("In email ID username doesn't seem to be valid.");
		return false;
	}

	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("In email ID 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("In email ID 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("In mail ID address must end in a well-known domain or two letter " + "country.");
		return false;
	}

	if (len<2) 
	{	
		//alert("In the email ID address is missing a hostname!");
		return false;
	}

	return true;
}