Put salt ,oil and 4 glass of water into the pot and boil it.Put the pasta into the boiling water and boil it for 12 minute.Same time cook the milk,flour and butter to prepare bechamel sauce.Then put eggs into the sauce and mix it.After that put the boiled pasta into the sauce and mix it again.Then put the pasta into a owen tray and put some cheese on top of it and cook again in the owen till cheese melt.