You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I serve you today?

USER: Can you please help me in changing my reservation?

ASSISTANT: Sure, may I know your name?

USER: I am Jack Williams.

ASSISTANT: Please wait for a minute.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us.