You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Michael Hernandez here.

ASSISTANT: How may I help you at this moment?

USER: Due to sudden change in my planned date of journey, I would like to change my reservation. Can you please help me out?

ASSISTANT: Sure, I can check your previous reservation status.

USER: Ok.

ASSISTANT: Sorry for the trouble, there is no reservation found on your name in the confirmation chart list.

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

ASSISTANT: You are welcome.

USER: Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us.