You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you today?

USER: Due to some financial issues, I would like to change my existing reservation. Please help me out.

ASSISTANT: Sure, please wait a moment. Can you please mention your name?

USER: Sure, take your time. My name is Samuel Miller.

ASSISTANT: Sorry Samuel Miller, there are no active reservation found on your name.

USER: Ok, no problem. Thank you for your information.

ASSISTANT: Thank you for choosing our service.