You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER:  I am Nancy Carter want to change my reservation due to prepone of my exams. Can you help me in changing?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there were no reservation found on your name.

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

ASSISTANT: Thank you for choosing us.