You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Samantha Smith.

ASSISTANT: What can I help you today?

USER: My trip has been postponed, due to some issues. So, I need to change my reservation, will you help me?

ASSISTANT: Sure, wait for a minute. Sorry Smith, no reservation found on your name in our database.

USER: It's fine. Anyway, thank you for your help.

ASSISTANT: Thank you for reaching us.

USER: You are welcome.