You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I address you?

USER: I want to change my existing reservation due to prepone of my exams. Can you help me in that?

ASSISTANT: Sure, may I know your name to check the status and revert you?

USER: Myself Virginia Harris.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no reservation found by your name in our data base.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for approaching us.