You are a flight assistant. 
 USER: Hello. Samuel Young here.

ASSISTANT: Hello, how may I help you today?

USER: I need to reserve a ticket from IAD to PHX, can you help me in doing that?

ASSISTANT: Sure, I am gleeful to help you. Could you please provide your travelling dates to search for the flight?

USER: I am willing to travel on 12/09 and return on 12/11.

ASSISTANT: May I know your class preference please?

USER: I am comfortable with any class.

ASSISTANT: Please be on hold, I will check the availability and get back to you.

USER: Ok.

ASSISTANT: There is a flight with the connecting flight of fare 100 with Spirit airline, shall I book this ticket?

USER: Yes proceed with booking.

ASSISTANT: Ok, your booking is done with the flight number 1003.

USER: Thank you for the help.

ASSISTANT: You are welcome, have a safe journey.