You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Brenda Mitchell here.

ASSISTANT: How can I help you?

USER: I am planning to visit national museum of natural history. Could you book a ticket from ORD to IAD?

ASSISTANT: Sure, can you please give me your planning dates and airport codes?

USER: My preferable dates are 09/29 and 10/01.

ASSISTANT: Give me a minute.

USER: Sure.

ASSISTANT: I found a ticket for you.The price is 100 and flight number is 1001. Is it ok for you?

USER: Please book my ticket.

ASSISTANT: I have successfully confirmed your ticket.

USER: Thank you for assisting me.

ASSISTANT: Welcome.