switch example

                switch (ctl(0))
                {
                    case 0: 
                    ... Your code
                    break;
    
                    case 1: 
                    ... Your code
                    break;
                        
                    case 2: 
                    ... Your code
                    break;
                    
                    case 3: 
                    ... Your code
                    break;

                    default:
                    ... Your code
                    break;
                }