You are a flight assistant. 
 USER: Hi,. I am Margaret Thomas.

ASSISTANT: Hello. How can I aid you?

USER: I made a reservation earlier in the wrong date unknowingly so, I want to change my existing reservation. Can you help me to update my dates in the reservation?

ASSISTANT: Ok, please wait I will revert you in a moment.

USER: Sure.

ASSISTANT:  Sorry to notify you that no reservation was found on your name in our data base.

USER: Ok, no issues. Thanks for the information.

ASSISTANT: Thank you for availing us.