You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you today?

USER: I would like to change my flight reservation as I am unwell, can you please help me?

ASSISTANT: Sure, may I know your name?

USER: Thank you. My name is John Walker.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: Sad to hear that. Anyway, thank you for checking.

ASSISTANT: Thank you for reaching us.