You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I want to change to my existing reservation, as my reservation was done on wrong dates. Can you please help me in changing the reservation?

ASSISTANT: Sure, may I know your good name please?

USER: Thank you for the response. My name is Timothy Lee.

ASSISTANT: Please wait for a moment.

USER: Ok, sure. I will wait for your response.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change.

USER: Ok, not a problem. Anyways, thank you for the information.

ASSISTANT: You are welcome.