You are a flight assistant. 
 USER: Hi, I am Andrew Taylor.

ASSISTANT: Hello, how may I assist you?

USER: I need to change my recent existing reservation due to bad weather condition in my city. Could you please help me in doing that?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

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

USER: No problem,thank you for helping me.

ASSISTANT: Thank you so much for choosing us. Have a good day.