You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, may I know your name please?

USER: I am Daniel Brown.

ASSISTANT: We found a reservation with your given name, please share your airport codes.

USER: My airport codes are SEA and PHL.

ASSISTANT: Let me know your travelling dates.

USER: I prefer to travel on Mar 24 and Mar 26.

ASSISTANT: May I know your connection limit?

USER: I prefer to travel in a connecting flight.

ASSISTANT: Do you have any other requirements?

USER: I would like to return back in afternoon.

ASSISTANT: Sorry, there are no flights found with your given details.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for opting us.