I understand that eCard is the best tool to do this in. Unfortunately I have not worked in the eCard yet. Furthermore, it seems nonetheless not as eCard really can do what I'm after.
I want the form to look like the pictures I sent in the first post.
I still think that one accept the terms feature should be standard in CSS Form Builder.
I've found a script that does what I'm looking for regarding calculation of the sum. This script also makes sure to double-check that the visitor has summarized. Otherwise, they see a dialog box. The problem is that this script appears to block CSS Form Builders validation.
The form is on the following page: operaform2013_SE2.php
Grateful for help!