Re: help me in cursors.

I am assuming you are using Forms 4.5.
Try declaring a record of cursor type,
and then assigning the values to forms variables. And If using forms4.5, you would need the NEXT_RECORD; and DBMS_OUTPUT will not work.

 DECLARE
 cursor c1 is

         select st_id, sample_date, time, compid, concentration
          from analyzed_samples1
         where st_id = :segments.st_id and
         (sample_date between :segments.firstdate and :segments.lastate);
  

 c1_rec c1%rowtype;   

 BEGIN   

         open c1;
         loop
  
                 fetch  c1 into c1_rec;
                 if c1%notfound Then
                      EXIT;
                 Else
  			:analyzed_samples3.st_id := c1_rec.st_id;
        	        :analyzed_samples3.sample_date:= c1_rec.sample_date;


	                :analyzed_samples3.time:= c1_rec.time;

	                :analyzed_samples3.compid:= c1_rec.compid;

	                :analyzed_samples3.concentration:= c1_rec.concentration;

        	         next_record;
                End if;
         end loop;
         synchronize;
         close c1;

-- 
"If you want what you've never had, 
 you must be willing to do what you've never done."