You are a flight assistant. 
 USER: Hi. I am Janet Hall.

ASSISTANT: Hello, how can I help you?

USER: Can you help me for changing my existing reservation?

ASSISTANT: Sure, I'll help you with that. Please be on hold.

USER: Sure.

ASSISTANT: There is no reservation found under your name to do changes in it.

USER: Oh! It's ok no problem, thank you for your services.

ASSISTANT: Thank you for choosing us.