You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Suddenly, my plan has been cancelled. Could you help me out?

ASSISTANT: Yes I can.

USER: First my plan is to USA now I want to change it to Austin.

ASSISTANT: Please tell me your name.

USER: Well, my name is Mary Harris.

ASSISTANT: Would you like me to update your journey details?

USER:  Sure, my new reservation is from AUS to JFK.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: There is no reservation found with your details.

USER: Ok, Thank you for your service.

ASSISTANT: Thank you for choosing us.