You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Actually, I want to change my existing reservation which is done recently due to some health issues, can you please help me?

ASSISTANT: Sure, may I know you name please?

USER: Ok,. My name is Matthew Roberts.

ASSISTANT: Matthew Roberts, can you give me a moment please?

USER: Sure, take it.

ASSISTANT: Matthew Roberts, sorry to inform that there is no reservation by your name.

USER: Ok, not an issue.

ASSISTANT: Thank you for reaching us.

USER: Anyways, thank you for your service.