You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Susan Robinson.

ASSISTANT: How can I help you?

USER: I am planning to visit Washington, can you please book me a ticket from SFO to IAD?

ASSISTANT: Can I know your travelling dates?

USER: I am planning my journey on the dates of May 16 and May 18.

ASSISTANT: Do you have any preference?

USER: Please ensure that depart flight is in the evening time.

ASSISTANT: Connecting flight can be booked with airline Spirit for price 100 having flight number 1011.

USER: Please reserve my ticket in this flight.

ASSISTANT: Your ticket is booked.

USER: Thank you for booking my ticket.

ASSISTANT: Thanks.