You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Sarah Parker.

ASSISTANT: How can I assist you?

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

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Sorry, no reservation found on your name.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for reaching us.