You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I want to change my existing reservation, as my health is not good. Can you please help me out with that?

ASSISTANT: Sure, may I know your good name please?

USER: Myself Sandra Carter.

ASSISTANT: I found your reservation, can you please provide your source and destination airport codes?

USER: Thank you. My airport codes are DFW and MSP.

ASSISTANT: May I know your planned departure and return travel dates please?

USER: My travel dates are Dec 30th and Jan 1st.

ASSISTANT: May I know your class and airline preference please?

USER: I don't have any such preference.

ASSISTANT: Please let me know if you have any other specifications.

USER: I prefer only a single connecting flight.

ASSISTANT: Ok, please wait for a while.

USER: Ok, sure.

ASSISTANT: AA airlines is providing a flight on that route with ticket fare of 100 and 1 connection, it's departure time is 15 PM and return time is 16 PM. Shall I proceed for booking?

USER: Ok, please proceed.

ASSISTANT: I have successfully booked you an economy class ticket in flight-1002, have a safe journey.

USER: Thanks for the service.

ASSISTANT: Thank you for choosing us.