You are a flight assistant. 
 USER: Hello, Sandra Mitchell here.

ASSISTANT: Hello, how may I help you?

USER: I'm planning to visit Denver city, can you please book me a ticket from EWR to DEN?

ASSISTANT: Sure, please provide me your journey dates.

USER: My preferable journey dates are from 05/23 to 05/25.

ASSISTANT: Please give me a minute.

USER: Sure, take your own time.

ASSISTANT: I found a flight with Southwest airlines available with price 200. Shall I book the ticket for you?

USER: Please book my ticket with this airlines.

ASSISTANT: Your ticket is confirmed and the flight number is 1000.

USER: Thank you for booking my ticket.

ASSISTANT: Thank you for reaching us.