You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you today?

USER: I want to change my existing reservation due to bad health issues, can you help me with that?

ASSISTANT: Sure, let me know your name please to check further?

USER: I am Samuel Nelson.

ASSISTANT: Please stand by.

USER: Sure.

ASSISTANT: Sorry, no reservation found with your given name in our database to change it.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for contacting us.