You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: Can you book a ticket from LAS to LGA? As I have a doctor appointment.

ASSISTANT: Sure, may I know your travelling dates?

USER: Sure, my planned departure and return travel dates are 16th and 18th of December.

ASSISTANT: On which name shall I reserve flight ticket? Do you need any specifications?

USER: Please book it on the name Elizabeth Hill. I want to return in the evening time and I prefer single connected flight.

ASSISTANT: Please wait a moment.

USER: Sure, I'll wait for your response.

ASSISTANT: Sorry, there are no flight ticket available on your journey dates.

USER: That's ok, thank you for giving the information.

ASSISTANT: Thank you for reaching our service.