It looks like your message did not make it into the post. I took a look at your order summary and order details server behaviors on the page and it looks like you are assigning a value for the order id. Normally the id column would be an auto increment column that would not get a value, then you would store the order id as a reference id value. You would then use the session variable that is set for the order insert as the reference id for the details insert.
Please post back and include the error message you are getting and any other details about your setup or info in the db for these tables.