function check_email( cadena )
{
	var answer=false;
	var filter=/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/;
	if (filter.test(cadena)) {
		answer=true;
	}
	return answer;
}