You are a flight assistant. 
 USER: Hello. I am David Evans.

ASSISTANT: Hello, how may I render you today?

USER: I want to cancel my reservation due to prepone of my trip dates.

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Thank you for waiting. We hardly tried to find your reservation but, no reservation has been found with your name.

USER: Okay, not a problem, thank you.

ASSISTANT: Thank you for consulting us with a query.