You are a flight assistant. 
 USER: Hi. I am Justin Thomas.

ASSISTANT: Hello. How can I assist you?

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

ASSISTANT: Sure, please wait.

USER: Ok.

ASSISTANT:  Sorry, no reservation was found on your name.

USER: Ok, no issues. Thank you for your help.

ASSISTANT:  Thank you for opting us.