function isEmail(obj) {
	var email = obj.value;
	var emailLength = email.length;
	var at_ok = 0;
	var dot_ok = 0;
	
	for(var i=0; i != emailLength; i++) {
		if (email.charAt(i) == ' ')	return false;
		if (email.charAt(i) == '@') at_ok += 1;
		if (email.charAt(i) == '.') dot_ok = 1;
		}
	if ((dot_ok == 1) && (at_ok == 1)) {
		return true; }
	else {
		return false;
		}
	}