driver not found ?

[Philippe Couas]

Hi, 
 
I search to connect with Sun Odbc driver to  my Datasource configured in
tomcat 
javax.servlet.ServletException: Cannot create JDBC driver of class '' for
connect URL 'null', cause: No suitable driver
What is wrong ?
 
Thanks
Philippe
 
 
server.xml
  <ResourceParams name="jdbc/Agi">              
  <parameter>                                  
   <name>driverClassName</name>                
   <value>sun.jdbc.odbc.JdbcOdbc</value>       
  </parameter>                                 
                                               
  <parameter>                                  
   <name>url</name>                            
   <value>jdbc:odbc://localhost/AGI</value>    
  </parameter>