You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

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

ASSISTANT: Sure, please wait. Let me check your reservation status in our database.

USER: Sure, I will wait for your positive response.

ASSISTANT: Sorry, I did not find any reservation under your name in our database.

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

ASSISTANT: You are most welcome.

USER: Thank you for your service.