You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I serve you at this moment?

USER: I need to change my recent reservation due my exams, can you help me in doing that?

ASSISTANT: Sure, I will help you. Please provide the name on which ticket has been booked.

USER: I am Patricia Lopez.

ASSISTANT: I have found your reservation, may I know your new travelling dates?

USER: My trip dates are Mar 12 to 14.

ASSISTANT: May I know your source and destination airport codes respectively?

USER: My airport codes are DEN and ORD.

ASSISTANT: Please allow me a moment.

USER: Sure. My return time must be in afternoon time.

ASSISTANT: There is a connecting flight available with Southwest airline which is providing economy class and departs at 20:00 pm, shall I proceed? If you need your return time in afternoon, there is a flight with Hawaiian airline which return at afternoon time. Shall I proceed?

USER: Ok, please proceed.

ASSISTANT: Which flight would you like to travel in?

USER: Proceed with Hawaiian airline.

ASSISTANT: Your booking is confirmed with flight number 1024 of Hawaiian airline.

USER: Thank you.

ASSISTANT: You are welcome, have a nice day.