You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am planning to change an existing reservation, due to health issue. Can you please change my reservation?

ASSISTANT: Sure, may I know your name?

USER: I am Stephen Clark.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: We found a reservation on your name, please tell me your details.

USER: I am planning to book a ticket from AUS to DEN.

ASSISTANT: Can you share me your planned travelling dates?

USER: I would like to travel on Feb 03 and return back on Feb 05.

ASSISTANT: Ok, Is there any connection limit?

USER: I am looking for a connecting flight.

ASSISTANT: May I know your airline preference?

USER: I am looking for a normal cost airline.

ASSISTANT: Ok, do you have any other specifications?

USER: No.

ASSISTANT: Sorry, there is no flights found with your planned dates.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for choosing us.