Linking two table..it is look like unpivot but it is not

Hi guys, I got a situation like this:

Table A

create table #fly (company varchar (50), period varchar(6), adcost (int), ppcost (int))

insert into #fly values ('PanAm', '201401', 100, 200) ,  ('PanAm', '201402', 200, 200) , ('PanAm', '201403', 700, 1000), ('EGAm', '201401', 1100, 1200), ('EGAm', '201402', 7100, 7200)                                                                                                                  Table 2 #Cost (firm varchar (100), client varchar (100), period varchar(6), element (varchar 10), tot int) insert into #firm ('Zuck', ''Panam', '201401', ''adcost', 40), ('Zuck', ''Eagam', '201401', ''adcost', 40), ('Zuck', ''Panam', '201402', ''ppcost', 240)                 As you can see I got in fly the field adcost that is a value in the table #cost. I need to link the two table and I'm wondering whitch is the best way. Another issue is the adcost (#fly) has in #cost two relatives adcost and fixadcost element. I should consider both the elements as adcost.  Advices? Thanks