You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you now?

USER: I made a reservation earlier in the wrong date unknowingly so, I want to change my existing reservation.

ASSISTANT: Sure, I am happy to help you with that.

USER: Can you please help me with this?

ASSISTANT: Sure, can I have your name please to check your reservation status?

USER: Sure, I am Dennis Baker.

ASSISTANT: Please wait a moment.

USER: Ok.

ASSISTANT: Sorry Dennis Baker, no reservation has found under your name to change.

USER: Ok, Thank you for your help.

ASSISTANT: Thank you for choosing us, have a good day.