function checkEMail(emailStr)
{
var emailPat=/^(.+)@(.+)$/ ;
var specialChars="\\(\\)<>@,;:\\\\\\\"\\.\\[\\]";
var validChars="\[^\\s" + specialChars + "\]";
var firstChars=validChars ;
var quotedUser="(\"[^\"]*\")";
var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/ ;
var atom="(" + firstChars + validChars + "*" + ")";
var word="(" + atom + "|" + quotedUser + ")";
var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");


var matchArray=emailStr.match(emailPat);
if (matchArray==null)
	return false;
	
var user=matchArray[1];
var domain=matchArray[2];

if (user.match(userPat)==null)
    return false;
	
var IPArray=domain.match(ipDomainPat);

if (IPArray!=null) 
	{
	for (var i=1;i<=4;i++) 
		{
	    if (IPArray[i]>255)
			return false;
		}
    return true;
	}

var domainArray=domain.match(domainPat);
if (domainArray==null)
    return false;
	
var atomPat=new RegExp(atom,"g");
var domArr=domain.match(atomPat);
var len=domArr.length;
if (domArr[domArr.length-1].length<2 || domArr[domArr.length-1].length>3) 
   return false;

if (domArr[domArr.length-1].length==3 && len<2) 
   return false;

return true;
}