select transno,itedesc,[Revenue Ton],weight,
total,classdesc,totalclass,[revenue total],
case when [Revenue Ton]+weight is not null then [Revenue Ton]+weight 
else [revenue total]
end AS revenuevalue
from
(
Select transac.transno,
itemmas.itedesc,
(given * 1.13260) as [Revenue Ton],weight,
case 
when weight = null then
(given * 1.13260)
else 
((given * 1.13260) + weight)
end 
as total,
classifi.classdesc,p.totalclass,p.[revenue total]
from transac 
inner join(itemmas inner join(itemdet 
inner join(classifi 
inner join 
(Select count(classifi.classdesc) as totalclass,sum((given * 1.13260)) as [revenue total],
classifi.classdesc from classifi
inner join(itemdet 
inner join transac on itemdet.itemno=transac.itemno)
on classifi.classno=itemdet.classno 
group by classifi.classdesc)p on classifi.classdesc=p.classdesc)
on classifi.classno=itemdet.classno) on itemmas.itemno=itemdet.itemno)
on transac.itemno=itemmas.itemno 
)t