You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am willing to change my existing reservation. Can you please help me for this?

ASSISTANT: Sure, may I know your good name please?

USER: Myself Larry Edwards.

ASSISTANT: Ok, please wait for a moment.

USER: Sure, I will wait for your kind response.

ASSISTANT: Sorry to say that, there was no reservation found with your given name.

USER: Not a big problem, anyhow thank you very much for checking the status.

ASSISTANT: Thank you for choosing us.