Saren / HKGolden redirect to forum15

// ==UserScript==
// @name        HKGolden redirect to forum15
// @namespace   Saren
// @description Let's redirect non-forum15 url to forum15
// @include     *.hkgolden.com/*
// @version     1
// @grant       none
// @run-at      document-start
// ==/UserScript==
var handleForum = function () {
  for (var i = 1; i <= 14; i++) {
    if (window.location.host.indexOf('forum' + i + '.') !== - 1) {
      window.location = window.location.href.replace('forum' + i + '.', 'forum15.');
      return true;
    }
  }
  return false;
}
var handleM = function () {
  for (var i = 1; i <= 5; i++) {
    if (window.location.host.indexOf('m' + i + '.') !== - 1) {
      window.location = window.location.href.replace('m' + i + '.', 'forum15.');
      return true;
    }
  }
  return false;
}
handleForum() || handleM();