You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out?

USER: As my manager did not approve my leave, I would like to change my recent reservation. Can you please help me out with that?

ASSISTANT: Sure, I will help you in changing the reservation. May I know your name please?

USER: Thank you, I have reserved it on the name of Samantha Mitchell.

ASSISTANT: Sorry, there are no reservations found in our database.

USER: Oh! I think the ticket was not booked due to server issue.

ASSISTANT: Thank you for reaching us.

USER: Anyway, thank you for the information.