You receive max_user_connections message when the maximum number of users allowed to connect the server are already there.
Here are the links for your references
http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html#sysvar_max_user_connections
http://dev.mysql.com/doc/refman/5.5/en/too-many-connections.html
You can either increase the number of connections allowed or
Instead of opening new connection for everyone. Why dont you use same connection for all queries.
