Transaction and DriverManagerXADataSource

[aby]

Hello everyone,
I am new to orion server and am trying to find out how to use
transaction handling within orion. Now within the datasource.xml file.
I have got something like this

<data-source
          class="com.evermind.sql.DriverManagerDataSource"
          name="OracleDS"
          location="jdbc/OracleCoreDS"
          source-location = "c:\orion\j2ee\home\orion.jar"
          xa-location="jdbc/xa/OracleXADS"
          ejb-location="jdbc/OracleDS"
          connection-driver="oracle.jdbc.driver.OracleDriver"
          username="scott"
          password="tiger"
          url="jdbc:oracle:thin:@192.168.0.5:1521:dcom"
          inactivity-timeout="30"
     />

In this case when I am using the code in the client as

InitialContext ic = new InitialContext();
DataSource ds = (DataSource)ic.lookup("jdbc/OracleDS");
Connection con = ds.getConnection();

then the pooled connection happens. As I understand there is a place where the 
transactions can be rolled back if an
'EJBException' is thrown by the container. Now the doubt is that this does not happen 
with the OracleDS.

So I thought that I should use the

class="com.evermind.sql.DriverManagerXADataSource" in the xml file

and in the client code use

DataSource ds = (DataSource)ic.lookup("jdbc/xa/OracleXADS");

The problem is that the server does not start saying that it needs the 
source-location. can anyone
help me out on this? Thanks

i would also like to know how to say 'transaction' required for one of the function of 
my EJB in orion.
I could do this in the J2EE RI using the deploytool, but I am totally lost here.

Thanks in advance

Regards
Aby