I have a spreadsheet with a series of drop down boxes with multiple values.  
Is it possible to set up a formula that will add only those cells adjacent to
certain values?  As an example, if the drop down has options such as PENDING
and CLOSED but I want to have the system automatically add only the dollar
amounts next to PENDING.  Then, when it changes to CLOSED, I would like the
system to automatically re-calculate and shift the specific amount from
PENDING to CLOSED, can that be done?  If so, how?  

Any assistance will be greatly appreciated.  Thanks.

J-P