You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I am Gary King as I need to change my existing reservation, can you help me with it?

ASSISTANT: Ok. Please wait for a while.

USER: Sure.

ASSISTANT: We did not found any reservation regarding your name.

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

ASSISTANT: Thank you for choosing us.