Comparing Contents of 2 tables in T-SQL

declare @cnt1 int 
declare @cnt2 int 
declare @cnt3 int 
declare @res bit 

select @cnt1 = count(*) from A 
select @cnt2 = count(*) from B 
select @cnt3 = count('x') 
     from (select * from A 
     UNION 
     select * from B) as t 

if (@cnt1 = @cnt2) and (@cnt2 = @cnt3) 
 begin 
   set @res = 1 
   print 'A = B' 
 end 
 else 
  begin 
    set @res = 0 
    print 'A <> B' 
  end 
go