Debian Wheezy, Postgresql 9.1.4, Oracle Java 7, Tomcat 7

I created a db naming it refbankdb, the owner is postgres.
I need to creat a user and associate the user with the database named refbankdb.
And I need the user to have list, read and write permissions.

What I'm asking is how do you associate the user with the database?

I'm using this link as a guide to create the user. www_postgresql_org/docs/9.1/static/app-createuser

createuser -c1 -D -E -l -R -S rfb_user

-c1 max number of connetions set to 1.
-D not allowed to create databases
-E encrypt the users password
-l user allowed to login Note:default behavior
-R user not allowed to create new roles
-S user will not be superuser

I'm trying to install this RefBank app. Can't post a proper URL because I'm new to forum.

vbrant_ipd_uka.de/RefBank/static/downloadRefBank

Snip from web.cnfg file:
// EXAMPLE for PostgreSQL (to activate, remove the double slashes from the start of the three lines below and fill in the angle-bracketed parts in the EasyIO.JDBC.Url line with your actual data)
//EasyIO.JDBC.DriverClassName = "org.postgresql.Driver";
//EasyIO.JDBC.DriverClassPath = "./postgresql-8.2-505.jdbc3.jar";
//EasyIO.JDBC.Url = "jdbcostgresql:<DatabaseNameInLowerCase>?user=<PostgreSqlUser>&password=<PostgreSqlPassword>";