I can't because my PC does not have free space at the hard disk. I tried and PC could not perform anything. Unfortunatelly I have the teacher who does not want to help in any way, just making thing more and more difficult for me. Anyway your suggestion to use MERGE was very helpful, I am still reading these texts and soon I will try again, to write new code. Then I will need your help again: to see and suggest further corrections. You are very kind and thanks a lot. 🙂