You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I want to travel from PHL to DEN. Can you help me to book a flight ticket?

ASSISTANT: Sure, may I know your travel dates?

USER: I want to fly in the flight on Jan 14 and Jan 16.

ASSISTANT: Do you have any specifications?

USER: I want to travel in a connecting flight.

ASSISTANT: Please share me your name.

USER: Donald White.

ASSISTANT: Sorry, there is no flight at this moment.

USER: That's ok. Anyways, thank you.

ASSISTANT: Thank you.