Rodolfo,

>Hi Jim,
>
>Have you looked at SDT?
>
>Yes, I have! ... But I don't want a complete product that have a lot of features... SDT is a very good solution, but I'm looking for a free solution...

Goog luck! I went down this same road recently, and decided my time was better spent. If you are talking minor structure changes, by all means roll your own. When you need more, you know where to go... :-)