Error establishing a database connection

That's what I did and the database 'wordpress' is accessible either from the putty shell either from phpMyadmin...I'm really trying to figure out what's wrong.I had sharing problems last week thinking it was due to my poor experience and then discovered that the cause was the last Radiator firmware (unfortunately after I already did a complete installation from zero....anyway...).To understand what's going on, things must be checked again one by one....I posted a topic under addon's which nobody answers to : from the page SQL of phpMyadmin,I would like to know how the server can be stopped and restarted...I mean the correct synthax command (I tried severals but always get an error).Finally I did a basic configuration of MySQL....may be there are some parameters which have to be setup....below is my.cnf file.....

[client]
port = 3306
socket = /var/run/mysqld/mysqld.sock

[mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0

[mysqld]
#
# * Basic Settings
#
user = admin is it right.....do I have to insert other users ?
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
language = /usr/share/mysql/english
skip-external-locking
skip-name-resolve
# Instead of skip-networking the default is now to listen only on
# localhost which is more compatible and is not less secure.
# bind-address = 127.0.0.1
# skip-networking
innodb_buffer_pool_size = 6M
key_buffer_size = 16k
myisam_sort_buffer_size = 16k
max_connection = 20
#
# * Fine Tuning
#
key_buffer = 16k
max_allowed_packet = 16M
thread_stack = 128K
#
# * Query Cache Configuration
#
query_cache_limit = 1048576
query_cache_size = 32768
query_cache_type = 1
#
# * Logging and Replication
#
# Both location gets rotated by the cronjob.
# Be aware that this log type is a performance killer.
#log = /var/log/mysql.log
#log = /var/log/mysql/mysql.log
#
# The following can be used as easy to replay backup logs or for replication.
#server-id = 1
#log-bin = /var/log/mysql/mysql-bin.log
# See /etc/mysql/debian-log-rotate.conf for the number of files kept.
max_binlog_size = 16384
#binlog-do-db = include_database_name
#binlog-ignore-db = include_database_name
skip-bdb
#
# * InnoDB
#
# InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.
# Read the manual for more InnoDB related options. There are many!

[mysqldump]quick
quote-names
max_allowed_packet = 16M

[mysql]
#no-auto-rehash # faster start of mysql but no tab completition

[isamchk]
key_buffer = 16M