public Customer authenticateCust(String em, String pas){
        Customer cust = null;
        for(Integer i : customers.keySet()){
            if(customers.get(i).getEmail().equalsIgnoreCase(em) && customers.get(i).getPassword().equals(pas)){
                cust = customers.get(i);
                break;
            }
        }
        return cust;
    }