You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Pamela Martin.

ASSISTANT: How may I aid you today?

USER: I am planning to change an existing reservation, due to health issue. Can you please change my ticket?

ASSISTANT: Sure, please be on hold.

USER: Sure.

ASSISTANT: Thank you for your time. Sorry, there is no reservation matching with your name in our portal to make changes further.

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

ASSISTANT: Thank you for reaching us.