You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I support you today?

USER: I am Linda Anderson and I want change an existing reservation due to sudden change in my trip.

ASSISTANT: Sure, please wait a while. I will check and get back to you.

USER: Ok.

ASSISTANT: Thank you for being wait. Unfortunately we found no reservation by your name.

USER: Ok. Thank you for your service.

ASSISTANT: Thank you for picking us.