function run_test() { var ioService = Components.classes["@mozilla.org/network/io-service;1"] .getService(Components.interfaces.nsIIOService); try { var linkService = Components.classes["@mozilla.org/network/network-link-service;1"] .getService(Components.interfaces.nsINetworkLinkService); // The offline status should depends on the link status do_check_neq(ioService.offline, linkService.isLinkUp); } catch (e) { // The network link service might not be available do_check_eq(ioService.offline, false); } }