You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Benjamin Evans.

ASSISTANT: Is there any help that you need from our travel agency?

USER: Due to an emergency case that I have to investigate I have to travel San Francisco. Can you help me in flight ticket booking?

ASSISTANT: Sure, I am here to help you with the ticket booking.

USER: Thank you for positive response.

ASSISTANT: Ok, may I know your planned departure and arrival dates of your journey?

USER: Sure, I have planned to departure on 04/16 and later completion of case I will catch the return flight on 04/18.

ASSISTANT: Ok, can you please mention your desired location airport codes?

USER: Sure, my desired airport codes are from DC-DCA to CA-SFO.

ASSISTANT: Ok, I have found a flight in UA airlines which is having a single stop over in between your journey and the ticket fare is 200. Shall I reserve your ticket with this flight?

USER: Good to hear that there is a flight on my planned dates, so please go ahead and confirm my flight ticket booking.

ASSISTANT: Ok, I have confirmed your ticket in the above mentioned airlines and the flight number is 1003.

USER: Thank you for your enormous help in my flight ticket booking.

ASSISTANT: You are most welcome. Thank you for reaching us. Have a nice day.

USER: Welcome.