You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Samuel Carter.

ASSISTANT: How may I assist you?

USER: Can you help me in booking from AUS to DCA, as there is a conference meeting to attend?

ASSISTANT: Yes, can you tell me your travelling dates?

USER: My trip dates are Apr 28 to Apr 30.

ASSISTANT: Do you have any other preferences?

USER: I need a connecting flight which depart in afternoon.

ASSISTANT: Give me a moment.

USER: Sure.

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

USER: No issue, thank you.

ASSISTANT: Thank you.