You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Joshua Miller. I want to change my existing reservation due to heavy rainfall, can you please help me with that?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: No problem, thank you.

ASSISTANT: Thank you for approaching us.