You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I assist you?

USER: I am Christine Thomas. Due to some health issues, I want to change my recent reservation. Will you help me in that?

ASSISTANT: Sure, Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Ok, thank you.

ASSISTANT: Thank you for availing us.