Thanks Gilad, it look good already. I did not specify but Voltinfo is pretty good actually and the final multiplication should indeed be applied to the result of sum.
So i inserted the codes var v1 till 4 in the different fields
and i inserted the event.value in the last field. Though it does not show an answer yet. How can i get this last thing done?
I inserted some pictures to show what i did. (text is in dutch but that doesn't matter;)).
Edit:
Filled in but lacking the answer.
How you can help me with this last part too:)