Where am I going wrong?
There's no way of knowing where you went wrong (IF you went wrong - your SQL looks fine to me) without a little more information. Things like:
1. Your database version (select * from v&version)
2. What did you expect? How is the result different from what you'd expect?
3. Some sample data (2 or 3 records of both tables), with the result you would expect from those records
Then we might be able to help you. Right now everything is guesswork, since we are not familiar with your data nor with your requirements.