getting error on starting chat-client: lib_md5 missing?

Hi, i am trying to execute chat clietn and geting the folowing error.
iam running it on linux.i did not find lib_md5.erl inth ecode i downloaded.

what i ned to make it run? here is te eror

make chat_client
mkdir -p /home/wasiq/.erlang_config/
cp conf /home/wasiq/.erlang_config/lib_chan.conf
make clean - clean up
erl -pa ../ -s chat_client test
Erlang (BEAM) emulator version 5.6 source async-threads:0 [kernel-poll:false]

Eshell V5.6 (abort with ^G)
1> chat_client disconnected unexpected:{‘EXIT’,<0>,normal}

=ERROR REPORT==== 28-Jan-2008::21:40:05 ===
Error in process <0> with exit value: {undef,[{lib_md5,string,[“pzbaplovtpmhazjuvcpdyqishAsDT67aQ”]},{lib_chan,authenticate,4},{lib_chan,connect,5},{chat_client,try_to_connect,4}]}

chat_client disconnected unexpected:{‘EXIT’,<0>, {undef, [{lib_md5,string,

{lib_chan,authenticate,4},
{lib_chan,connect,5},
{chat_client,try_to_connect,4}]}}

thanks
wasiq

lib_md5.erl:

%% ---
%%  Excerpted from "Programming Erlang" 
%%  Copyrights apply to this code. It may not be used to create training material, 
%%  courses, books, articles, and the like. Contact us if you are in doubt.
%%  We make no guarantees that this code is fit for any purpose. 
%%  Visit <a href="http://www.pragmaticprogrammer.com/titles/jaerlang">http://www.pragmaticprogrammer.com/titles/jaerlang</a> for more book information.
%%---
-module(lib_md5).

%% modfied to use BIFs

-export([string/1, file/1, bin/1, binAsBin/1, digest2str/1]).

-define(BLOCKSIZE, 32768).
-define(IN(X,Min,Max), X >= Min, X =< Max).

%% md5:string(string())      -> BinDigest
%% md5:file(FileName)        -> {ok, BinDigest} | {error, E} 
%% md5:digest2str(BinDigest) -> StringDigest

%% md5:file works with chunks so should work correctly with extremely
%% large files

string(Str) -> digest2str(erlang:md5(Str)).

file(File) ->
    case file:open(File, [binary,raw,read]) of
    {ok, P} -> loop(P, erlang:md5_init());
    Error   -> Error
    end.

loop(P, C) ->
    case file:read(P, ?BLOCKSIZE) of
    {ok, Bin} ->
        loop(P, erlang:md5_update(C, Bin));
    eof ->
        file:close(P),
        {ok, erlang:md5_final(C)}
    end.

digest2str(Digest) -> bin2str(binary_to_list(Digest)).

bin2str([H|T]) ->
    {H1, H2} = byte2hex(H),
    [H1,H2|bin2str(T)];
bin2str([]) ->
    [].

byte2hex(X) -> 
    {nibble2hex(X bsr 4), nibble2hex(X band 15)}.

nibble2hex(X) when ?IN(X, 0, 9)   -> X + $0;
nibble2hex(X) when ?IN(X, 10, 15) -> X - 10 + $a.

%% compute the md5 checksum of a binary
bin(Bin) ->
    C1 = erlang:md5_init(),
    C2 = erlang:md5_update(C1, Bin),
    C3 = erlang:md5_final(C2),
    digest2str(C3).

binAsBin(Bin) ->
    C1 = erlang:md5_init(),
    C2 = erlang:md5_update(C1, Bin),
    erlang:md5_final(C2).