anchor.diff:  	    {error, Reason}
       end.
   
  +%% @doc Returns the current balance for a customer.
   -spec getbalance(Key::term()) -> error | number().				  
   getbalance(Key) ->
       case rpc:call(?SERVER, floppy, read, [Key, riak_dt_pncounter]) of	
  
positive.code: 	    {error, Reason}
      end.
  
  -spec debit(Key::term(), Amount::non_neg_integer()) -> ok | {error, string()}.
  debit(Key, Amount) ->
      case rpc:call(?SERVER, floppy,  append, [Key,{{decrement,Amount}, actor1}]) of
  
negative.code: -export([credit/2, debit/2, init/2, getbalance/1, buyvoucher/2, usevoucher/2, readvouchers/1]).
  
  -define(SERVER, 'floppy@127.0.0.1').
  %% @doc Initializes the application by setting a cookie.
  init(Nodename, Cookie) ->
      net_kernel:start([Nodename, longnames]),
      erlang:set_cookie(node(),Cookie).
  
  %% @doc Increases the available credit for a customer.
  -spec credit(Key::term(), Amount::non_neg_integer()) -> ok | {error, string()}.  
  credit(Key, Amount) ->
      case rpc:call(?SERVER, floppy, append, [Key,{{increment,Amount}, actor1}]) of
  