You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you today?.

USER: I am Alexander Lewis. I want to book a flight ticket from LGA to SFO. Could you help me in booking?

ASSISTANT: Sure, on which dates to prefer to start and return on?

USER: My preferable dates are from 10/06 to 10/08.

ASSISTANT: Thank you for your details, currently there are no flights found with the given details.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you.