You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: John Campbell here. Can you book my ticket in a direct flight?

ASSISTANT: Yes, can I know your nearest airport codes?

USER: My airport codes are ORD and SEA.

ASSISTANT: Ok, could you tell me your dates of travelling?

USER: My itinerary dates are 03/21 and 03/23.

ASSISTANT: Give me a moment.

USER: Sure.

ASSISTANT: Sorry to inform you that there are no flights found on your requested dates.

USER: No problem, thank you for helping me.

ASSISTANT: Thank you for reaching us.