LinuxQuestions.org - Samba user problem

Hey guys...
I need help setting user accounts in samba, I already have configured for share folder this is my smb.conf file

[global]
# workgroup = NT-Domain-Name or Workgroup-Name
workgroup = CVS
security = share

# server string is the equivalent of the NT Description field
server string = Linux Server

# This option is important for security. It allows you to restrict
# connections to machines which are on your local network. The
# following example restricts access to two C class networks and
# the "loopback" interface. For more examples of the syntax see
# the smb.conf man page
; hosts allow = 192.168.0. 192.168.1. 127.

# if you want to automatically load your printer list rather
# than setting them up individually then you'll need this
printcap name = /etc/printcap
load printers = yes

# It should not be necessary to spell out the print system type unless
# yours is non-standard. Currently supported print systems include:
# bsd, sysv, plp, lprng, aix, hpux, qnx
; printing = bsd

# Uncomment this if you want a guest account, you must add this to /etc/passwd
# otherwise the user "nobody" is used
; guest account = pcguest

# this tells Samba to use a separate log file for each machine
# that connects
log file = /var/log/samba/%m.log

# Put a capping on the size of the log files (in Kb).
max log size = 50

# Security mode. Most people will want user level security. See
# security_level.txt for details.
# Use password server option only with security = server
; password server = none

# Password Level allows matching of _n_ characters of the password for
# all combinations of upper and lower case.
; password level = 8
; username level = 8

# You may wish to use password encryption. Please read
# ENCRYPTION.txt, Win95.txt and WinNT.txt in the Samba documentation.
# Do not enable this option unless you have read those documents
; encrypt passwords = yes
; smb passwd file = /etc/samba/smbpasswd

# The following are needed to allow password changing from Windows to
# update the Linux system password also.
# NOTE: Use these with 'encrypt passwords' and 'smb passwd file' above.
# NOTE2: You do NOT need these to allow workstations to change only
# the encrypted SMB passwords. They allow the Unix password
# to be kept in sync with the SMB password.
; unix password sync = Yes
; passwd program = /usr/bin/passwd %u
; passwd chat = *New*UNIX*password* %n\n *ReType*new*UNIX*password* %n\n *passwd:*all*authentication*tokens*updated*successfully*

# Unix users can map to different SMB User names
; username map = /etc/samba/smbusers

# Using the following line enables you to customise your configuration
# on a per machine basis. The %m gets replaced with the netbios name
# of the machine that is connecting
include = /etc/samba/smb.conf.%m

# Most people will find that this option gives better performance.
# See speed.txt and the manual pages for details
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192

# Configure Samba to use multiple interfaces
# If you have multiple network interfaces then you must list them
# here. See the man page for details.
; interfaces = 192.168.0.1/24 192.168.1.1/24

# Configure remote browse list synchronisation here
# request announcement to, or browse list sync from:
# a specific host or from / to a whole subnet (see below)
; remote browse sync = 192.168.0.1 192.168.2.255
# Cause this host to announce itself to local subnets here
; remote announce = 192.168.0.1 192.168.2.255

# Browser Control Options:
# set local master to no if you don't want Samba to become a master
# browser on your network. Otherwise the normal election rules apply
local master = yes

# OS Level determines the precedence of this server in master browser
# elections. The default value should be reasonable
; os level = 64

# Domain Master specifies Samba to be the Domain Master Browser. This
# allows Samba to collate browse lists between subnets. Don't use this
# if you already have a Windows NT domain controller doing this job
domain master = yes

# Preferred Master causes Samba to force a local browser election on startup
# and gives it a slightly higher chance of winning the election
preferred master = yes

# Enable this if you want Samba to be a domain logon server for
# Windows95 workstations.
; domain logons = no

# if you enable domain logons then you may want a per-machine or
# per user logon script
# run a specific logon batch file per workstation (machine)
; logon script = %m.bat
# run a specific logon batch file per username
; logon script = %U.bat

# Where to store roving profiles (only for Win95 and WinNT)
# %L substitutes for this servers netbios name, %U is username
# You must uncomment the [Profiles] share below
; logon path = \\%L\Profiles\%U

# All NetBIOS names must be resolved to IP Addresses
# 'Name Resolve Order' allows the named resolution mechanism to be specified
# the default order is "host lmhosts wins bcast". "host" means use the unix
# system gethostbyname() function call that will use either /etc/hosts OR
# DNS or NIS depending on the settings of /etc/host.config, /etc/nsswitch.conf
# and the /etc/resolv.conf file. "host" therefore is system configuration
# dependant. This parameter is most often of use to prevent DNS lookups
# in order to resolve NetBIOS names to IP Addresses. Use with care!
# The example below excludes use of name resolution for machines that are NOT
# on the local network segment
# - OR - are not deliberately to be known via lmhosts or via WINS.
; name resolve order = wins lmhosts bcast

# Windows Internet Name Serving Support Section:
# WINS Support - Tells the NMBD component of Samba to enable it's WINS Server
; wins support = no

# WINS Server - Tells the NMBD components of Samba to be a WINS Client
# Note: Samba can be either a WINS Server, or a WINS Client, but NOT both
; wins server = w.x.y.z

# WINS Proxy - Tells Samba to answer name resolution queries on
# behalf of a non WINS capable client, for this to work there must be
# at least one WINS Server on the network. The default is NO.
; wins proxy = no

# DNS Proxy - tells Samba whether or not to try to resolve NetBIOS names
# via DNS nslookups. The built-in default for versions 1.9.17 is yes,
# this has been changed in version 1.9.18 to no.
dns proxy = yes

# Case Preservation can be handy - system default is _no_
# NOTE: These can be set on a per share basis
; preserve case = no
; short preserve case = no
# Default case is normally upper case for all DOS files
; default case = lower
# Be very careful with case sensitivity - it can break things!
; case sensitive = no

[Beta]
comment = Welcome to my Beta Network File Shared Folde

path = /Beta
public = yes
writable = yes
printable = no

Now how can make a single user to access a folder, but it will be exclusively for that user who can access the folder. User is in XP