static void Main()
 {
     Application.EnableVisualStyles();
     Application.SetCompatibleTextRenderingDefault(false);
     do
     {
         if (MainClass.appStatus == "" || MainClass.appStatus == "open")
         {
             Login     loginInstance = new Login();
             MainClass main          = MainClass.getInstance();
             if (!File.Exists(MainClass.path + "\\cnt"))
             {
                 Settings settings = new Settings();
                 Application.Run(settings);
                 if (settings.status == "")
                 {
                     break;
                 }
             }
             else
             {
                 Application.Run(loginInstance);
                 if (loginInstance.getStatus())
                 {
                     MDI mdi = new MDI();
                     MainClass.setMDI(mdi);
                     Application.Run(mdi);
                 }
                 if (MainClass.appStatus == "exit")
                 {
                     break;
                 }
             }
         }
     } while (MainClass.appStatus != null);
 }