Address Logic

[johny.cbi]

Address Logic

addr1= Mailstop [X1]
addr2= street address [X2]
addr3 = P.O. Box [X3]

[X1] [X2] [X3]

for some mails there will be street address, suite number, P.O.Box number.  for some mails we'll see only number and
address

I need the logic for X1 is null it has to show X2 other wise X3, If X2 is null it has to show X1 and X3

I think there will be 8 ways for this logic

can you share your ideas ?