Hi,
I made a page /app with a shoppingart feature, so people can select items from gallery 1 and they collect them in gallery 2.
It works fines with a simple collect code, but now i want something extra...
Is it possible that if someone select something from gallery 1, its going to check if there is a same item in gallery 2, and if there is a double item, it wont add them at the gallery but add +1 add the amount field in my gallery (it is a text label) like this:

left is what i got now.. Right is what i want.
I hope there are options to make this. Thanks!