You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: I want change my existing reservation, as my exams got postponed. Can you please help me out in changing my existing reservation?

ASSISTANT: Yes, can you share me your name?

USER: Thank you for the response, my name is Mary Baker.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: Ok, not an issue. Anyways, thank you for the information.

ASSISTANT: Thank you for contacting us.