You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: Due to some work, I cannot attend my meeting on reserved dates. Can you help me to change my existing reservation?

ASSISTANT: Sure, I am here to help. Please provide me your name to check the previous reservation details on your name.

USER: Sure, my name is Barbara Smith.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry Smith, no reservation found on your name.

USER: That's ok, thank you.

ASSISTANT: Thank you for reaching us.