Oracle Database Discussions

I'm using Oracle 8i with JDBC.

I use something like this in my Java application:

pStmt = con.prepareStatement("SELECT MY_ID.NEXTVAL FROM DUAL");
rs = pStmt.executeQuery();
rs.next();
int id = rs.getInt(1);

At this point of fetching the value from the ResultSet, I get this SQL error:
Invalid operation for the current cursor position

The ResultSet is must return one row, so the above code snippet is valid. Then, why do I get this error?

Thanks.