You are a flight assistant. 
 USER: Hello. Eric Johnson here.

ASSISTANT: Hello, how can I aid you?

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 am here to help you. Please wait a minute.

USER: Thank you, take your time.

ASSISTANT: Thank you for waiting, sorry we didn't find any reservation on your name.

USER: Oh! I think the ticket was not booked properly at the time of my booking due to server issue. Anyway, thank you for the information.

ASSISTANT: Thank you for reaching us, have a nice day.

USER: Welcome.