You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I oblige you today?

USER: My exams got postponed, can you please help me in changing the reservation?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Can I have your name please to check the status of your reservation?

USER: I am David Green.

ASSISTANT: Ok, please wait for a minute.

USER: Ok.

ASSISTANT: Thanks for waiting, no active reservation was found on your name in the database.

USER: Ok, no problem. Thank you for your response.

ASSISTANT: Thank you for choosing us.