I have no idea where to start on this one. I would like the user to click a button and have a form open. This form would allow them to enter 1 or multiple products and the quantity of each and get the resulting total weight. I have a table with 2 columns; product and weight. I am thinking something like the image below but I am not sure if this is the best way to go about it at all.
As always any advice would be appreciated