Thanks so much for putting up with my silliness, since I named each form entry the exact same as each table column, I wasn't able to tell that the list of names on the left side of the dialog referred to the database not the form fields. I am glad at least to be spared the list of embarrassing mistakes I found after my initial posting before anyone saw it.
Unfortunately, changing the second filter reference in the update php to post and rebinding the columns to the form fields didn't make it work. So I guess there is some other dumb mistake I made still in there. I've uploaded a revised file.