You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,.

USER: My name is Rebecca Brown.

ASSISTANT: How may I help you?

USER: I want to change my recent reservation due to my health issue. Can you help me with that?

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: I regret, there is no reservation by name Rebecca Brown.

USER: Ok, No problem. Thanks for the information.

ASSISTANT: Have a nice day!.