function _check_email(email) {
      var pattern = /^(.+)@(.+)$/;
      var atom = "\[^\\s\\(\\)<>#@,;:!\\\\\\\"\\.\\[\\]\]+";
      var word="(" + atom + "|(\"[^\"]*\"))";
      var user_pattern = new RegExp("^" + word + "(\\." + word + ")*$");
      var ip_pattern = /^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
      var domain_pattern = new RegExp("^" + atom + "(\\." + atom +")*$");

      var arr = email.match(pattern);
      if (!arr) return "Email address seems incorrect (check @ and .'s)";
      if (!arr[1].match(user_pattern)) return "The username doesn't seem to be valid.";

      var ip = arr[2].match(ip_pattern);
      if (ip) {
              for (var i=1; i<5; i++) if (ip[i] > 255) return "Destination IP address is invalid!";
      }
      else {
              if (!arr[2].match(domain_pattern)) return "The domain name doesn't seem to be valid.";
              var domain = arr[2].match(new RegExp(atom,"g"));
              if (domain.length<2) return "This address is missing a hostname!";
              if (domain[domain.length-1].length<2 || domain[domain.length-1].length>3)
                    return "The address must end in a three-letter domain, or two letter country.";
      }
      return false;
}<div class='small'>[이 게시물은 관리자님에 의해 2011-10-31 16:57:14 JavaScript에서 이동 됨]</div>