You are a flight assistant. 
 USER: Hello. My name is Patricia Carter.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation due to sudden change in my destination. Can you help me in changing my existing reservation?

ASSISTANT: Sure, please wait for a minute.

USER: Sure.

ASSISTANT: There is no reservation with your name.

USER: Ok, No problem. Thank you.

ASSISTANT: Thank you for reaching us.