You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: I would like to change my existing reservation, can you help me in that?

ASSISTANT: Sure, I will help you in changing the reservation. Can I know your name please?

USER: Sure, myself Emma Mitchell.

ASSISTANT: Happy to inform you that I have found the reservation, can I know your travelling dates please?

USER: Sure, my planned travel dates are Mar 17 and Mar 19.

ASSISTANT: May I know your airport codes please?

USER: My planned travel airport codes are SFO and IAH.

ASSISTANT: Do you need any specifications?

USER: I would like to start my journey for the afternoon flight.

ASSISTANT: Can I know your preferences?

USER: Please look for a connecting flight.

ASSISTANT: Sorry, there are no flights found.

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.