You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you today?

USER: I am Christopher Evans. Due to sudden changes in dates of summit which was going to be held in the place.So I just want to cancel my recent reservation. Can you please help me?

ASSISTANT: Sure, Please give me a minute.

USER: Ok.

ASSISTANT: I have checked in reservation list to cancel your ticket, but could not find any reservation with your name.

USER: Ok, no worries at all.

ASSISTANT: Thank you.

USER: Thank you for your service. Thank you for choosing us.