You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I want to change my existing reservation. Could you help me with that?

ASSISTANT: Please share your name?

USER: Elizabeth White here.

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

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for contacting us.