You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: Betty Wright here. Could you book my ticket in a direct flight?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: I will be leaving on June 14 and returning on June 16.

ASSISTANT: Can I know your airport codes too?

USER: I will be travelling from LGA to OAK.

ASSISTANT: Sorry, there are no flights found.

USER: No problem, thank you.

ASSISTANT: Thank you for reaching us.