You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: Yes, can you tell me your name?

USER: Sure, my name is Emma Smith.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: Ok, not an issue. Thank you for checking.

ASSISTANT: Thank you for contacting us.