You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I serve you?

USER: I would like to change my existing reservation due to the weather conditions.

ASSISTANT: Ok, please let me know your good name.

USER: My self Mark Davis.

ASSISTANT: Please wait a minute.

USER: Ok.

ASSISTANT: Thanks for being patient. Sorry, there is no reservation found with your name.

USER: No issue. Thank you for your response.

ASSISTANT: Thank you for choosing us.