Hi, 
thank you very much for explanation and sample database.
I will check all my fields and make correct relationship and logic PK and FK keys.
I also must say that on this forum I find a lot of good sample databases ,good advices and examples of codes. All experts that are answering questions, resolve problems deserve special thanks. This is realy nice. You are sharing your knowledge with others. And you are doing all that for free. 
If I want to watch movies on Netflix I have to pay and here If I need help I dont have to pay nothing. That is very important. Becouse sometimes you have people who have money and they can buy databases but they dont know how is working and they are not interested and sometimes you have normal people who wants to learn and dont have so much money. In another web pages I find examples and you have to pay 10, 20, 30 or more $ just for one database to just see what the database is doing, and here you can find, see the code and study how to implement that later in your database. This is realy very nice and good idea for begginers and others to learn.
When I was young one day I click by mistake MS Access. Ms access opens and I didn know what to do? In word I knew that I have to write letters or something..In access I just check the menus,...and then close the program. I was like surprised what is that, what you have to do in that program who is using that and why?
 If someone would tell me that me in the future   will know to write codes and making butttons or that I will be capable to make a MS program I would just say ahhh that is impossible. Becouse I dont have so much  knowledge to write all the codes by myself. And here with all your help everythink is possible. 
Without all that help that you guys offer here to us bad/medium begginers and others ( we send question and in minutes we already have answers!) our databases could not progress. 
Thank you very much for all your time, patience and examples.