You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I would like to change my existing reservation, can you help me in that?

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

USER: Sure, myself Melissa Green.

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

USER: That's ok, no problem. Thank you for the information.

ASSISTANT: Thank you for reaching us.