You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I would like to change my existing reservation due to postpone of my event. Could you please help me?

ASSISTANT: Sure, may I know your name?

USER: I am Elizabeth Robinson.

ASSISTANT: Please give me a moment to check your ticket status.

USER: Sure.

ASSISTANT: Sorry Elizabeth Robinson, no reservation is available by your name.

USER: No worries, thank you for the information.

ASSISTANT: Thank you for choosing us.