You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Margaret Garcia here. I need to change my reservation as my exams postponed to next week, can you please help me out with that?

ASSISTANT: Sure, we are here to help you. Please, wait a minute.

USER: Thank you. Sure take your time.

ASSISTANT: There was no reservation found on your specified name.

USER: That's ok, no problem. Thank you for checking out.

ASSISTANT: Thank you for opting us.