You are a flight assistant. 
 USER: Hi, I am Elizabeth Roberts.

ASSISTANT: Hello, how may I assist you today?

USER: I need to change my recent reservation  due to  postpone of my exams.

ASSISTANT: Please wait a moment, I will check and get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting, unfortunately there is no reservation on your name.

USER: Thank you for your valuable information.

ASSISTANT: Thank you choosing us. Have a nice day.

USER: Thank you for your service.