You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I aid you today?

USER: I am Lisa Roberts, I would like to change my existing reservation because while booking last time I gave wrong airport codes for that reason I would like to change, so can you help me in this?

ASSISTANT: Sure Lisa.

USER: Thank you.

ASSISTANT: Please wait for a moment, I will check your previous reservation.

USER: Ok, I will wait for your response.

ASSISTANT: Sorry Lisa, I have not found any reservation under your name.

USER: Oh! it is ok, no problem.

ASSISTANT: Thank you for contacting us.

USER: Most welcome but thank you for your quick response.

ASSISTANT: Have a nice day.