You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Mary Taylor.

ASSISTANT: How can I aid you?

USER: Can you help me in booking from PHL to LAS, as there is a business meeting to attend?

ASSISTANT: Sure, may I know your planned travel dates to check for the flight availability?

USER: My trip dates are Nov 15 to Nov 17.

ASSISTANT: Do you have any specifications?

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

ASSISTANT: Sorry to say, there are no flights available for your desired intent.

USER: No issue, thank you.

ASSISTANT: Thank you for reaching us.