You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you today?

USER: I want to change my existing reservation. Could you help me with that?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Can you please share me your name to proceed further?

USER: Jerry Collins here.

ASSISTANT: Thanks for providing your name, please wait for a while I will check in the previous reservation list and get back to you.

USER: Sure, take your time.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: That's ok, no problem. Thank you for helping me.

ASSISTANT: Thank you for choosing us.