You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I need to travel from PHL to IAH, can you help me in reserving a ticket?

ASSISTANT: Sure, please share me your trip dates.

USER: My trip dates are Dec 18 to 20.

ASSISTANT: Do you need direct flight or connecting flight?

USER: I need a direct flight.

ASSISTANT: May I know your airlines preferences?

USER: I am comfortable in any airline.

ASSISTANT: For booking, we need your good name. Please mention it.

USER: Joshua Davis here.

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

USER: Ok, no issues. Thank you for the information.

ASSISTANT: Thank you for opting us.