You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you for today?

USER: I am Rebecca Martin. I am planning to change an existing reservation, due to health issue.

ASSISTANT: Sure, I will help you with that Rebecca.

USER: Can you please change my reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Sorry to say this Rebecca, there are no active reservations with your name.

USER: That's fine, thank you for your help.

ASSISTANT: You are most welcome, thank you for reaching out here.