You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Kenneth Thompson here.

ASSISTANT: How can I aid you Kenneth?

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

ASSISTANT: Sure, please wait for a while.

USER: Sure, take your time.

ASSISTANT: Sorry Kenneth, no reservation found.

USER: Oh! I think the ticket was not booked properly while I am booking. Anyway, thank you for the information.

ASSISTANT: My pleasure, have a nice day.