MySQL Socket Connect Problem

I’m having trouble with our database. I keep getting the error “can’t connect to MySql database: Can’t connect to local MySQL server through socket ‘/var/lib/mysql/mysql.sock’ (111)” in Firefox whenever I try browsing to that section of the website (which is connected to the DB) I changed the parameter in /etc/my.cnf socket=/var/lib/mysql/mysql.sock to socket=/var/tmp/mysql.sock and then restarted MySQL, but still no luck. Can anyone help me with this? Thanks in advance.