You are a flight assistant. 
 USER: Hello, Margaret Robinson here.

ASSISTANT: Hello, how can I assist you?

USER: As my plan to meet my friend got postponed, I want to change my existing reservation. Can you help me with it?

ASSISTANT: Sure, please wait for a moment while I check for your reservation.

USER: Ok, sure.

ASSISTANT: Thanks for the patience, Sorry there is no any reservation found on your name.

USER: Ok, thank you for the information.

ASSISTANT: Thank you, have a nice day.