You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: As my plan to go for Cable Car Museum got postponed, so I want to change my existing reservation. Can you help me with it?

ASSISTANT: Sure, we are here to help you. Can you please let me know your name to check whether the reservation is existed?

USER: Sure, my name is Sandra Hall.

ASSISTANT: Please give me a minute, I will go through with the reservation list and let you know.

USER: Ok.

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

USER: That's ok, thank you for the response.

ASSISTANT: Thank you, have a nice day.