You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am Larry Williams.

ASSISTANT: Ok.

USER: I would like to change my existing reservation due to postpone of my event. Could you please help me?

ASSISTANT: Sure, I am here to help you. Please stand by.

USER: Ok.

ASSISTANT: Thank you for waiting, sorry to inform no reservation found on your name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for reaching us, have a nice day.