You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am planning to visit Museum of Nature and Science at Denver, could you please help me with booking a flight ticket from PHL to DEN?

ASSISTANT: Sure, may I know your trip dates?

USER: I would like to depart on Apr 7th and return on Apr 9th.

ASSISTANT: Do you prefer a direct or connecting flight?

USER: I would be comfortable with single stopover.

ASSISTANT: Do you have any specifications?

USER: I have no other specifications.

ASSISTANT: May I know your name?

USER: I am Jack Adams.

ASSISTANT: Sorry Jack Adams, no flights are available on your route.

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you for choosing us.