You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jason Hernandez.

ASSISTANT: How may I lend a hand to?

USER: I want to change my existing reservation due to some health issues, can you help me with that?

ASSISTANT: Jason Hernandez, I am here to help you for this. Let me check your reservation status in our database.

USER: Sure.

ASSISTANT: I found a your reservation. May I know your airport codes?

USER: My airport codes are CLT and PHX.

ASSISTANT: Could you please share me your travel dates?

USER: My preferable journey dates are Dec 22 and Dec 24.

ASSISTANT: At what time are you planning to depart and return?

USER: I would like to return back in the afternoon.

ASSISTANT: Is there any other specification regarding your journey?

USER: I prefer connecting flight for this trip.

ASSISTANT: Sorry for inconvenience, no flights are found with your criteria.

USER: No problem, thank you for the information.

ASSISTANT: Thank you very much for contacting our agency.