Formula help to create Inventory

[Donutderek]

I'm working on an inventory sheet that pulls from received items on Sheet #2 .

I have a couple of cells that contain variable (items) and I want to know if there's a way to have them added or subtracted from sheet 2 totals.

Explained:
sheet1, B7 contains either "shipped" or "returned".
G13 contains products, ie: "paper", "plastic"
G14 contains a QTY.

sheet2, B50 contains total numbers of on-hand "paper".

What I want to know is there a way to formulate once "shipped" is selected, and "paper", can the qty in G14 be subtracted from my total on sheet 2, B50? Alternatively, if plastic etc.

Then if "returned" is in B7 can those quantities be ADDED back into inventory?

I'm pretty good with some of these formulas, but this one is complicated and has me stumped. Any help is greatly appreciated.

 

[kweaver]

Could you post an example of what the first sheet looks like?

 

[Donutderek]

Thanks for the reply- I'm not sure how to do that in this forum. I can try to do so tomorrow when I'm back at my laptop if it will help to clarify.