You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Carol Green.

ASSISTANT: How can I serve you?

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

ASSISTANT: Ok please wait a while.

USER: Sure.

ASSISTANT: Thanks for your time. We didn't found any reservation by this name.

USER: Ok, no problem at all.

ASSISTANT: Thank you for choosing us.

USER: Thanks for the information.