Getting oid after insert

Hi all

I am struggling to get the following code bit to work. It is supposed to be part
of getting the oid of the last insert. Can anyone see what I'm doing wrong
please? (Apart from using Java I mean....)

Thanks
Statement stmt=conn.createStatement();
stmt.executeUpdate(sqlStatement);
org.postgresql.ResultSet result =
(org.postgresql.ResultSet)stmt.getResultSet();
String statusString =result.getStatusString();
System.out.println( "Status string returned: "+statusString );

I get the following error:

***Exception:
java.lang.NullPointerException
java.lang.NullPointerException
at celerity.DBase.executeSQL(DBase.java:82)
at DBTest.main(DBTest.java:16)

it does compile fine. Removing all the above lines and leaving just this:
Statement stmt=conn.createStatement();
stmt.executeUpdate(sqlStatement);

inserts the rows fine.

Thanks

Ciao

Zak