You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I want to change my existing reservation due to some health issue. Can you help me?

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

USER: Thank you.

ASSISTANT: For changing the reservation. May I know your name please?

USER: Yes, I am Katherine King.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry to inform, no reservation is found with your criteria.

USER: Ok, not an problem. Thank you for your information.

ASSISTANT: Thank you very much for reaching us.