Trouble with Expression

[kctxucop08]

I am working on an inventory database needed for medication samples for an indigent clinic. I am new to Access and know my limits so I did begin with a template.


I would like to be able to maintain a perpetual intentory. There are several transactions that are possible and I have a table which reflects this (samples, sample distribution, original balance, expired meds). Where I have run into trouble is that I need to distinguish between the quantity of the transaction and the actual quantity which affects our inventory. For example, expired meds may be a quantity of 7, but the actual quantity for our inventory is -7. I do not know how to write an expression that expresses each transaction.

So far I've got, which is not yielding a quantity:
Actual Quantity: IIf([Transaction Types].[Add/Remove]="Addition",[Inventory Transactions]!Quantity,-([Inventory Transactions]!Quantity))

Any further help in the right direction would be much appreciated.

[goodguy]

I am working on an inventory database needed for medication samples for an indigent clinic. I am new to Access and know my limits so I did begin with a template.
I would like to be able to maintain a perpetual intentory. There are several transactions that are possible and I have a table which reflects this (samples, sample distribution, original balance, expired meds). Where I have run into trouble is that I need to distinguish between the quantity of the transaction and the actual quantity which affects our inventory. For example, expired meds may be a quantity of 7, but the actual quantity for our inventory is -7. I do not know how to write an expression that expresses each transaction.

So far I've got, which is not yielding a quantity:
Actual Quantity: IIf([Transaction Types].[Add/Remove]="Addition",[Inventory Transactions]!Quantity,-([Inventory Transactions]!Quantity))

Any further help in the right direction would be much appreciated.

#What are you getting? From what I see above, you are subtracting the same field from itself and to make matters worse, you have a redundant comma in it.