create proc ap_delme as
begin
      declare @aaa    int
      print 'test1'
      if @aaa = null
              select @aaa =  22 
      select @aaa = null
      select @aaa =  0 
      raiserror  25000  /*raise error in line 9 (could be any error)*/
      return  0 
end

 >isql -STEST -Usa -P*** -Dtest
1> ap_delme
2> go
test1
Msg 25000, Level 16, State 1:
Server 'TEST', Procedure 'ap_delme', Line 7:
Script error occured.
(return status = 0) 

   if @aaa = null   /*put the comment here*/
         select @aaa =  22 
   select @aaa = null /*and here*/

 
>isql -STEST -Usa -P*** -Dtest
1> ap_delme
2> go
test1
Msg 25000, Level 16, State 1:
Server 'TEST', Procedure 'ap_delme', Line 9:
Script error occured.
(return status = 0)