You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. I'm happy to assist you for the day.

USER: I am Debra Martinez, want to change my existing reservation. Will you please help me?

ASSISTANT: I'm sorry to hear that, let me check your existing reservation first.

USER: Sure.

ASSISTANT: Can I know your current locations and dates for further booking?

USER: My airport codes will be from DCA to JFK.

ASSISTANT: What will be your dates?

USER: My dates of journey will be from 03/23 to 03/25.

ASSISTANT: Flight 1002 is available for you. Shall I book it for you?

USER: Ok, please confirm my booking.

ASSISTANT: Your booking confirmed by AA airlines. Keep reaching us anytime you required.

USER: Thank you for your help. Sure.