I have the following scenario:
List "Items" contains some available items that can be ordered, and their respective prices:
Item Price
-------- ----------
Pencil 10
Eraser 5
Paper 7
Another list "Orders" has a lookup field into "Items" that allows for multiple values. This gives the user a form with checkbox where she just ticks of the items that she wants.
So far so good.
Now I need a field on "Orders" that stores the prices from the "Items" list as an accumulated number (a sum) on the "Order".
So if the user for example ticks of "Pencil" and "Paper", then the value 17 should be stored in a "Sum" field on "Order".
How can I accomplish this?
Regards
Leif