MS CRM 2011 - Inhering data from from form to another form

As you can see from the picture.

I want to add a new waste product to the current form using add new waste product button. That works well. Now only inherited info from current form is the weigh-in number, seen on under the product section.

Now I want to inherit more info to the waste product form from the current form like net weight. How can I do that? The relation between current form and waste product form is 1:N.