You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, I am here to assist you. Please help me with your name.

USER: My previous reservation has done with the name Mary Taylor.

ASSISTANT: Thank you. Please wait, let me check your reservation status in our database.

USER: Sure, take your own time.

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

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: You are welcome and thank you for choosing us.