You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Katherine Martinez.

ASSISTANT: How can I assist you today?

USER: I would like to change my existing reservation, which is done recently. Can you please help me out?

ASSISTANT: Sure, I can help you with that. Please wait for a while.

USER: Thank you for considering my request and will wait for your response.

ASSISTANT: Katherine Martinez, there is no active reservation found under your name to do modifications in that.

USER: Not a big problem, anyway thank you for the information.

ASSISTANT: Thank you for choosing us, have a nice day.

USER: Thank you for your service.