You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello.

USER: I am Jeffrey Wright.

ASSISTANT: how may I assist you?

USER: I want to alter my reservation, due to postponement of concert to be held at the place where I wanted to visit. Can you please help me changing my reservation?

ASSISTANT: Please wait for a while.

USER: Ok.

ASSISTANT: Sorry Wright, no reservation found on your name. Thank you for reaching us.

USER: Thank you for your service.