You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Daniel Harris here.

ASSISTANT: In which way I can 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 with that?

ASSISTANT: Sure. I will help you with that. Please wait a moment, I will check your previous reservation status.

USER: Thank you, take your time.

ASSISTANT: There is no previous reservation available under your name.

USER: Oh! I think the ticket was not booked due to server issue. Anyway, thank you for the information.

ASSISTANT: You are welcome Daniel Harris.