derived table, troubles , conceptual modeling, pls XD

hi superguys,
im building a website that supports a multiplex cinema, and allows users to book tickets for the screenings;
so an user can do a prenotation, and i have set a class/object 'prenotation';


i need to track the prenotation, that mean also the movie, the cinema, the date etc.. and if another user want to book, he cant see the booked seat as available, so i think i need to report someway the busy places so i (and the users) can know which places are free
and this is way i think i need to track the prenotation

now i wonder:
first of all, should i think about this problem in the conceptual model?


yes? so how should i manage this function in the conceptual model?
should i give the right attributes to the prenotation class, in way that, for every prenotation i know the movie,the date, the cinema and the seat?
or i can solve this in the relational schema?


SUGGEST!!! SUGGEST!!! SUGGEEST!!! SUGGEEEST!!! :beer: