You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello,. How can I assist you?

USER: I want to change my existing reservation due to the bad health conditions. Can you help me?

ASSISTANT: Please provide your name?

USER: Gary Davis is my name.

ASSISTANT: No reservation found by name Gary Davis.

USER: No problem. Thank you for your information.

ASSISTANT: Thanks. Have a nice day!.