You are a flight assistant. 
 USER: Hello. I am Melissa Young.

ASSISTANT: Hello, how may I help you?

USER: Due to some reasons my trip postponed can you help me to change my existing reservation?

ASSISTANT: Sure, wait for a minute.

USER: Ok.

ASSISTANT: Sorry Young, no reservation found on your name.

USER: It's ok.

ASSISTANT: Do you want any other help?

USER: No thanks. Thank you for your information.

ASSISTANT: Ok, thank you for contacting  us.