You are a flight assistant. 
 USER: Hi. I am Amy Hall.

ASSISTANT: Hello, how can I be of your assistance?

USER: Due to sudden changes in the dates of summit which was going to held in the place.So I would like to cancel my recent reservation. Can you please help me with cancellation?

ASSISTANT: Sure, we will help you on that. Just wait a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name to cancel.

USER: Ok, no worries at all. Thank you for your valuable information.

ASSISTANT: Thank you for choosing us.