You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you today?

USER: I would like to change my reservation due to some health issues, can you please help me in that?

ASSISTANT: Sure, I am glad to help you with that.

USER: Thank you.

ASSISTANT: Please, share me your name to check your reservation status.

USER: Myself Alexander Nelson.

ASSISTANT: Ok, please wait for a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to say that, we have not found any active reservation found on your name in our database.

USER: Thant's ok, no problem. Anyway thank you fro checking out.

ASSISTANT: Thank you for choosing us.