You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: My business meeting got postponed due to some problems in meeting place, can you please change my reservation?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can I know your name to check the reservation?

USER: I am Joseph Brown.

ASSISTANT: Please wait a minute, I will check and revert you.

USER: Sure, I 'll wait.

ASSISTANT: Sorry to say that there is no reservation found on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for choosing us.