You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Myself Samantha Jackson.

ASSISTANT: How can I assist you today?

USER: I want to change my existing reservation due to some health issues. Can you please help me?

ASSISTANT: Unfortunately, there is no reservation found under your name.

USER: It's ok. Thank you for your information.

ASSISTANT: Thank you for reaching us, have a great day.