function emailCheck (emailStr) {
		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)
			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>4)
			return false;
		if (len<2)
		   return false;
		return true;
	}