I'm working on a legacy project which connect to an older version sql server , my SQL Server version is 2008 R2, I encountered a problem which when I tried to insert the records within a datawindow in a PowerBuilder program, it triggered a trigger in a table  , at the same time it update another table which trigger another trigger as well,  it went wrong in the second table trigger. the tricky part was debugging a trigger ,any idea how to deal with this problem?

my first trigger

ALTER Trigger  [table1_Insert] 
On  [table1] For Insert
As
.........
.........
declare @ln_lestnum numeric(12,4)
declare @ln_num  numeric(9,3)
if exists (select att_no from inserted where source='in' and att_no <> '' and LOWER(LEFT( att_no, 3)) ='bac' )
begin
 -- here is trigger anotehr table update trigger
   update s 
      set s.process_num = s.process_num + i.process_num,
      s.is_process = case when s.back_num  - i.process_num > 0.000001 then 'yes' else 'ok' end
      from inserted i,secondtable s  
      where ltrim(rtrim(i.att_no)) =  ltrim(rtrim(s.back_no)) and  
      i.prod_no = s.prod_no and 
      i.prod_add = s.prod_add and 
      i.batch_no = s.batch_no 
      if @@rowcount = 0 
       begin
          print('errors encountered update returning goods numbers')
          eturn
       end
  end 

 here is my second trigger for update

ALTER trigger [secondtable_update]
on  [secondtable]
for update
as

declare @ln_lestnum numeric(9,3)
declare @ln_newbacknum  numeric(9,3)
declare @ln_oldbacknum  numeric(9,3)
declare @ls_prodno char(8),@ls_batchno char(12),@ls_prodadd char(12)

select  @ls_prodno = i.prod_no,@ls_batchno=i.batch_no,@ls_prodadd=prod_add,
        @ln_newbacknum  = i.back_num from inserted i
select  @ln_oldbacknum = d.back_num from deleted  d

--here is I had trying to print the variable value for kinda debugging but it doesn't work, all the values seems were null or empty
print('prodno '+@ls_prodno+' batchno'+@ls_batchno+' prod_add'+ @ls_prodadd)  
 
return
..........

any helps or suggestions will be appreciated .