You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I need to change an existing reservation due to my trip got post pone. Can you help me with this?

ASSISTANT: Sure, may I have your name please?

USER: I made a reservation by this name David Phillips.

ASSISTANT: Ok, please wait.

USER: Sure.

ASSISTANT: Thanks for your time, no reservation found on the name of Davis Phillips.

USER: Ok, not an issue. Thank you for your information.

ASSISTANT: Thank you for reaching us.