You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation due to bad health issues, can you help me out?

ASSISTANT: Sure, may I know your name please?

USER: I am Jeffrey Jackson.

ASSISTANT: Sorry, there was no reservation found with your given name.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for reaching us.