{
  // Check the grid proxy.
  if ( system("check_proxy") ) {
    cerr << "rootlogon: Proxy check failed--exiting root" << endl;
    gROOT->ProcessLine(".q");
  }

  // Load the dataset and DIAL libraries.
  gROOT->ProcessLine(".X load_dial.cxx+");

  // Load the macro for opening root datasets.
  gROOT->LoadMacro("open_root.C");

  // Load the DIAL command macro.
  gROOT->LoadMacro("dialcom.C");

  // Load credential.
  cout << endl;
  dset::GssCredentialManager::set_default();
  pprint(dset::GssCredentialManager::credential());

  // Instantiate XML parser and create DTD.
  XmlParser parser;

  // Define location of Unique ID generator files.
  string dial_uids = Environment::current().value("DIAL_UIDS");
  UniqueIdGenerator::set_generator(dial_uids);

  // Instantiate the catalogs.
  dset::DatasetRepository&
    dr = dset::DatasetRepository::default_instance();
  dset::DatasetFileCatalog&
    dfc = dset::DatasetFileCatalog::default_instance();
  dset::DatasetSelectionCatalog&
    dsc = dset::DatasetSelectionCatalog::default_instance();
  dset::DatasetReplicaCatalog&
    drc = dset::DatasetReplicaCatalog::default_instance();
  dial::ApplicationRepository&
    ar = dial::ApplicationRepository::default_instance();
  dial::ApplicationSelectionCatalog&
    asc = dial::ApplicationSelectionCatalog::default_instance();
  dial::TaskRepository&
    tr = dial::TaskRepository::default_instance();
  dial::TaskSelectionCatalog&
    tsc = dial::TaskSelectionCatalog::default_instance();
  dset::CredentialSelectionCatalog&
    csc = dset::CredentialSelectionCatalog::default_instance();
  dial::JobRepository&
    jr = dial::JobRepository::default_instance();

  // Following is informative but a bit slow.
  //show_catalogs();

  // Define global variables to reference the current application,
  // task and dataset.
  dial::ApplicationId aid;
  dial::TaskId tid;
  DatasetId did;
  const dial::Application* papp = 0;
  const dial::Task* ptsk = 0;
  const dset::Dataset* pdst = 0;
  const dial::JobPreferences* pprf = 0;

  // Define global job ID.
  dial::JobId jid;
  if ( FileStatus("jid").is_readable() ) {
    jid = JobId(Text("jid").line(0));
  }

  // Create client scheduler.
  string sconn = Environment::current().value("DIAL_SCHEDULER");
  if ( FileStatus("scheduler").is_readable() ) {
    Text tsch("scheduler");
    sconn = tsch.line(0);
  }
  if ( ! sconn.size() ) {
    cout << "DIAL_SCHEDULER is undefined" << endl;
    cout << "Using default scheduler" << endl;
    sconn = "http://dial02.usatlas.bnl.gov:20011";
  }
  cout << "Connecting to analysis service at" << endl;
  cout << "  " << sconn << endl;
  dial::WsClientScheduler msch(sconn);
  msch.set_timeout(5);

  // Welcome message.
  cout << endl;
  system("cat welcome.txt");
  cout << endl;

  // Execute user logon.
  if ( FileStatus("userlogon.C").is_readable() ) {
    cout << "Executing user logon" << endl;
    gROOT->ProcessLine(".X userlogon.C");
  }

  cout << "\nWelcome " << dset::GssCredentialManager::owner() << endl;

}