You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: Could you please change my existing reservation?

ASSISTANT: I will help you please share your name to proceed further?

USER: I am Kimberly Clark.

ASSISTANT: There is no active reservation found as per your preferences at the moment.

USER: No problem, thank you.

ASSISTANT: Thank you for choosing us.