You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I had done flight ticket booking last week to spend my holiday vacation with my family.

ASSISTANT: Ok.

USER: But, due to some weather conditions I would like to change my booking which I have done. Can you help me with this?

ASSISTANT: sure, may I know your name please?

USER: I am Charles Wilson.

ASSISTANT: Unfortunately, there is no reservation found with your name to change.

USER: It's ok, no issues. Thanks for your helping.

ASSISTANT: Thank you for choosing us.