You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: Could you please book a flight ticket from PHL to LAS?

ASSISTANT: Sure, I am happy to help you. Please let me know your travelling dates.

USER: My travelling dates are Apr 11 and Apr 13.

ASSISTANT: Do you prefer any stopover in between journey?

USER: I need a direct flight.

ASSISTANT: Are there any other specifications for you?

USER: No.

ASSISTANT: May I know your good name?

USER: My name is Kimberly Lewis.

ASSISTANT: Sorry, no flights are available on your journey routes.

USER: Not a problem, thank you.

ASSISTANT: Thank you for contacting us.