Hello,

Actually, there is no way to enforce foreign keys in MySQL, because this is a
pseudo-referential database language. You cannot use constraints like
"idtop_art references id_top".

The problem is in your code: the idtop_art field does not receive a value,
because of one or more of the following reasons:
1. On the page that inserts articles, you have not defined a dynamic menu with
all the topics.
2. The topics dynamic menu does not get its values from id_top and its labels
from title_top, as it should.
3. The insert form was not modified, so as to set the value of the idtop_art
field to the value from the menu.

Please revisit this section:
[url]http://www.macromedia.com/devnet/mx/dreamweaver/articles/php_blog1_11.html[/url]

Good luck!