if :iso_process.process_no is null or :iso_process.process_no = '' 
or  :iso_process.process_name is null or :iso_process.process_name = ''
or :iso_process.DOC_LINK is null or :iso_process.DOC_LINK = ''then
 begin 
  al_id := Find_Alert('Alert1');
  Set_Alert_Property(al_id, alert_message_text, 'You have to   
  fill all yellow fields');
  al_button := Show_Alert( 'Alert1');
  Raise form_trigger_failure;

exception
 when others then
  message(sqlerrm);
  message(sqlerrm);
end;