cannot get referential integrity to work

[sfullman]

Hello,

I'm using mysql 4.0.15-standard, and phpMyAdmin-2.5.6 to administer. Phpmyadmin is a good educational tool for starting to work with InnoDB relations, but I've got a problem...

I have both tables set as InnoDB tables. Also I have both the child and parent fields indexed -- I'm looking at it in front of my face.

However, when I go to the "Relation view" in phpMyAdmin and try to set the child field to refer to the parent field (I typically use ON DELETE CASCADE ON UPDATE CASCADE) and click submit, the message I get back is 'No Index Defined! [Foreign_key_fieldname_here]'

Any ideas? I'm making sure there are no orphaned child rows in the child table so that's not it.

Thanks,
Sam Fullman