function trim(str)
{
	s = str.replace(/^(\s)*/, '');
	s = s.replace(/(\s)*$/, '');
	return s;
}

function isEmailValid(email)
{
	var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (!filter.test(email)) {
		return false;
	}
	return true;
}