You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you at this moment?

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

ASSISTANT: Sure, I will help you with this.

USER: Thank you.

ASSISTANT: George Clark, there is no active reservation found under your name in our database.

USER: Oh! I think the ticket was not booked properly while I am booking.

ASSISTANT: Thank you for contacting us.

USER: Anyway, thank you for the information.