You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I am Anna Smith. I just want to change an existing reservation as my meeting got post pone due to some technical issues. Can you help me with it please?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there was no reservation found on your name.

USER: That's ok. Thank you for the response.

ASSISTANT: Thank you for choosing us.