Newbie: Deploying .war file, getting it working with MySQL

I am tring to get an web site that I have developed with Java Studio Creator working on a VPS. I cannot get tomcat to comunicate with the MySQL database. I have got a minimal web site working, and I have added a simple dtabase query to it and I get the error at [1] (for full error see http://205.234.144.63:8080/minimal/). I have got a simple java app. working with MySQL.

What I have done;

Put the minimal.war file in /usr/local/jakarta/jakarta-tomcat-5.5.9/webapps.
Put in a Context tag in server.xml file relating to the .war file [2]. This is expanded by tomcat.
Put in a Realm tag relating to the jdbc driver [3].

You can see my .war file at http://www.geocities.com/hughmorgan72/minimal.zip. It requires a database called smsserver, with a table called unit, with a column called name.

Versions;
Apache Tomcat/5.5.9
Java Studio Creator 2004Q2 Version 9
Linux server.imecserver1.com 2.4.20-021stab028.24.777-enterprise #1 SMP Fri Jan 6 19:39:27 MSK 2006 i686 athlon i386 GNU/Linux

Any suggestions? Thanks very much, my boss is breathing down my neck.

[1]
javax.servlet.ServletException: javax.servlet.jsp.JspException: javax.faces.FacesException: org.apache.tomcat.dbcp.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for connect URL 'null'

[2]
<Context path="/minimal" docBase="minimal" debug="0"
reloadable="false" crossContext="true">
</Context>

[3]
<Realm className="org.apache.catalina.realm.JDBCRealm"
driverName="com.mysql.jdbc.Driver"
connectionURL="jdbc:mysql://localhost/authority"
connectionName="root" connectionPassword="ROOT_PASSWORD"
userTable="users" userNameCol="user_name" userCredCol="user_pass"
userRoleTable="user_roles" roleNameCol="role_name" />