// Some form validation functions used often

var defaultEmptyOK = false;
var whitespace = " \t\n\r";
function isEmpty(s){
	return ((s == null) || (s.length == 0));
}
function isWhitespace (s){   
	var i;
	if (isEmpty(s)) return true;
	for (i = 0; i < s.length; i++){   
		var c = s.charAt(i);
		if (whitespace.indexOf(c) == -1) return false;
	}
	return true;
}
function isEmail (s){
	if (isEmpty(s)) {
		if (isEmail.arguments.length == 1) return defaultEmptyOK;
		else return (isEmail.arguments[1] == true);
	}
	if (isWhitespace(s)) return false;
	var i = 1;
	var sLength = s.length;
	while ((i < sLength) && (s.charAt(i) != "@")){ 
		i++;
	}
	if ((i >= sLength) || (s.charAt(i) != "@")) return false;
	else i += 2;
	while ((i < sLength) && (s.charAt(i) != ".")){ 
		i++;
	}
	if ((i >= sLength - 1) || (s.charAt(i) != ".")) return false;
	else return true;
}