private void user_add(String[] cmd) throws IOException {
   if (cmd.length == 3 && logged) {
     if (DBAccount.getInstance().isAccountExist(cmd[1]))
       OutputWrite("user_add=error;message=Account esistente");
     else {
       boolean b = DBAccount.getInstance().registra(cmd[1], cmd[2]);
       if (b) OutputWrite("user_add=OK");
       else OutputWrite("user_add=error;message=Errore durante la registrazione");
     }
   } else OutputWrite("user_add=error");
 }
 private void user_delete_username(String[] cmd) throws IOException {
   if (cmd.length == 2) {
     if (logged) {
       boolean del = DBAccount.getInstance().cancellaAccount(cmd[1]);
       OutputWrite("user_delete_username="******"OK" : "error"));
     } else {
       OutputWrite("user_delete_username=error");
     }
   } else {
     OutputWrite("user_delete_username=error");
   }
 }
 private void user_delete_id(String[] cmd) throws IOException {
   if (cmd.length == 2) {
     if (logged) {
       try {
         Integer id = Integer.parseInt(cmd[1]);
         boolean del = DBAccount.getInstance().cancellaAccount(id);
         OutputWrite("user_delete_id=" + (del ? "OK" : "error"));
       } catch (NumberFormatException e) {
         OutputWrite("user_delete_id=error");
       }
     } else {
       OutputWrite("user_delete_id=error");
     }
   } else {
     OutputWrite("user_delete_id=error");
   }
 }