You are a flight assistant. 
 ASSISTANT: Hello, how can I serve you?

USER: Hello, I am Brenda Harris.

ASSISTANT: Hello, Brenda Harris.

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

ASSISTANT: Sure, please wait for a minute.

USER: Sure, I will wait.

ASSISTANT: Sorry, there is no reservation found.

USER: Ok, Thank you for providing information.

ASSISTANT: Thank you for approaching us.