You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I want to change my existing reservation, can you please help me with this?

ASSISTANT: Sure, we are here to help you with this. Could you please let me know your name to check the reservation list?

USER: Rachel Edwards here.

ASSISTANT: Ok, give me some time to check the reservation status.

USER: Sure.

ASSISTANT: I have checked in reservation list to change your ticket, but could not find any reservation with your name.

USER: No problem, thank you.

ASSISTANT: Thank you for availing us.