You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Actually, I have done booking last week to attend my cousin wedding.But, in mean while my exams dates are arrived.So, I am willing to change my existing reservation.Can you help me to change my reservation?

ASSISTANT: Sure, may I know the name on which the reservation has been done?

USER: Yes, I am Nancy Young.

ASSISTANT: Sorry Nancy, there is no reservation found on your name.

USER: Oh! it might me cancelled before by my mother but it is not informed by her.

ASSISTANT: Ok fine.

USER: Thank you for the information.

ASSISTANT: You are welcome.