my name is Rodrigo and I'm from Argentina. So I apologize for my English

I've been using LyX for a while and I have a little inconvenience that ruins my papers! When I generate a bibliography and then quote in a book or paper document I get something like that: (author?) and then the number of the quote. I tried everything but I don´t know how erase "(author?)" to put myself the info or how to do to automatic recognition author and date by the program.
Thanks for your help!
Saludos!!!