You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: I need to change my reservation due to postponed of my sister engagement.

ASSISTANT: Ok.

USER: Can you help me with changing reservation?

ASSISTANT: Sure, I am here to assist you. May I have your name?

USER: David Edwards is my name.

ASSISTANT: Thanks for sharing your name. We did not find your name in the reservation list.

USER: Ok, no issues. Thanks for your service.

ASSISTANT: Thank you for reaching us.