You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

USER: I want to change my existing reservation.Can you help me for that one?

ASSISTANT: Sure, can you please let me know your name?

USER: Sure, Nancy Jackson here.

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

USER: No issues, thank you for the information.

ASSISTANT: Thank you for reaching us.