You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Lisa Brown.

ASSISTANT: How may I assist you?

USER: Can you please help me in changing my existing reservation, as my exam got postponed.

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Please wait a moment, I will check the status of your reservation.

USER: Ok.

ASSISTANT: Lisa Brown, no reservation has been found on your name in our records.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for reaching us.