You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Can you please help me to book a flight from PHL to DEN?

ASSISTANT: Sure, can I know your good name please?

USER: I am Karen Gonzalez.

ASSISTANT:  When you are willing to travel?

USER: I want to depart on Nov 18 and need to return on Nov 20.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a direct flight.

ASSISTANT: Is there any time concern?

USER: My depart time must be in the morning.

ASSISTANT:  Would you let us know if you have any other preferences?

USER: I prefer an normal-cost airline to travel.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for connecting with us.