You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I help you?

USER: I need to change my existing reservation some health issues, can you please help me with that?

ASSISTANT: Sure, we are here to help you. May I know your name please?

USER: Thank you. Michelle Carter.

ASSISTANT: Sorry to inform you that there is no active reservation on your given name.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thanks for contacting us.