AdoDB: how to determine OID of inserted row with Execute()

Hello everyone,

I'm using AdoDB to create a PHP interface to a PostgreSQL db. I have a
problem when inserting a row. I do something like this:

  connect_to_db();
  $return = $db->Execute("insert into foo values ('bar'));
  if ($return === false) {
    echo $db->ErrorMsg();
  } else {
    show_row($oid) // here's the problem
  }

When I do a succesful INSERT in pgsql, the OID of the inserted row is
echoed. However, according to the manual, the Execute() method allways
returns a recordset. I did a serialize() on $return to see if the OID
is there somewhere, but it isn't. I need the OID to be able to display
the row (with show_row()) after it's inserted.

Does anybody know how to determine the OID of an INSERTed row when
using AdoDB? TIA!