Modifying PowerStore Admin Page: product insert

Hello!
I've added some database fields to my database and some of them are text - and others are additional image files. Everything displays on my final pages perfectly. (I've been adding the additional data manually in MyPhpAdmin.)

I have modified my Product_Insert.php page to insert additional text database fields. When I did a test with just an additional text field - it actually processed the page correctly. All of the pre-existing "out-of-the-box" data fields "took." But the new data field did not insert into my database.

When I tried to add an insert image file field, the page failed. I get an error that the ProductThumb field cannot be blank. So I'm assuming that this is a bit different than updating the text insert behavior?

What I did for adding the text insert field is I added a text field to the page. I named it appropriately so that it matched the database field name. I then chose the Insert Record behavior from the Server Behaviors tab in Dreamweaver. (Originally when I did this - it wasn't seeing the database connection, so I had to establish that - which I did successfully.) Then in the Server Options frame I chose the lightning bolt and linked the text field form to the proper database field. And upon testing this - it did not insert the data into the database field.

What am I missing for the insert behavior here? That's the only thing that isn't working at the moment.

Many Thanks!

Carlene