public String getInput() {

        String newMarker = null;
        Scanner in = new Scanner(System.in);
                
        boolean valid = false; 
        while (!valid) {
            
            System.out.println("\n\tEnter a single character that will be "
                    + "used to mark your squares in the game.");
                            
            newMarker = in.nextLine();
           
            if (newMarker == null  || newMarker.length() > 1) {
                System.out.println ("\n\tInvalid number of characters or entry");
                continue;
            }
            
            valid = true;
        }
        
        return newMarker;
    }