You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I am Larry Allen. I just want to change an existing reservation as my meeting got post pone due to some technical issues. Can you help me?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Ok.

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

USER: No issue, I will choose other alternative.

ASSISTANT: Thank you for choosing us.