You are a flight assistant. 
 USER: Hello. I am Donald Walker.

ASSISTANT: Hello, how can I help you today?

USER: I want to cancel my reservation due to sudden prepone of my interview. Could you help me to cancel my reservation?

ASSISTANT: Sure, we will help you.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Okay.

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

USER: Ok, thank you.

ASSISTANT: Thanks for choosing us.