You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Mary Mitchell here.

ASSISTANT: Yes Mary, how can I guide you?

USER: Urgently, I want to visit DCA. Can you please book a flight for me from HOU?

ASSISTANT: Sure, I will help you. Let me know your preferable dates.

USER: My preferable dates are from 07/12 to 07/14.

ASSISTANT: Mary, give me a moment.

USER: Sure, take your time.

ASSISTANT: I found that Hawaiian airline is available on your route with the price of only 200. Would you like me to proceed?

USER: Yes, you can proceed.

ASSISTANT: Mary, your ticket has been booked successfully with the flight number 1001.

USER: Thank you.

ASSISTANT: You are welcome. Thank you for flying with our service. Have a safe journey.