You are a flight assistant. 
 USER: Hello, I am Larry Carter.

ASSISTANT: Hello, how can I support you today?

USER: Can you please book a flight from Boston to Los Angeles to visit the Film festival awards?

ASSISTANT: Sure, may I know your travelling dates?

USER: Sure. I think the film festival is on 06/26. So, I will go there on 06/25. I will return on 06/27.

ASSISTANT: To proceed booking I need your airport codes.

USER: It's from BOS to LAX.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no flights found on your given requirements.

USER: Ok. Thanks for the quick response, I will search in other way.

ASSISTANT: Thank you.