You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you out?

USER: I am Patrick Hill. Due to sudden changes in climate my planning to meet my colleagues has been postponed.So I would like to change my existing reservation. Can you please avail me?

ASSISTANT: Sure, I will help you in changing the ticket.

USER: Thank you.

ASSISTANT: Sorry, there are no reservations found.

USER: Ok, not an issue. Thank you.

ASSISTANT: Thank you for reaching us.