You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Michelle Harris here.

ASSISTANT: How can I assist you?

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

ASSISTANT: Sure, please give me a minute.

USER: Ok, take your time.

ASSISTANT: Sorry, there is no reservation available on your name.

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

ASSISTANT: Than you for reaching us.