You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Myself Charles Allen.

ASSISTANT: Charles, how may I help you?

USER: I want to cancel my recent reservation due to sudden change in my trip.

ASSISTANT: Sure, please wait for a while.

USER: Ok, take your own time.

ASSISTANT: Sorry, no reservation is available by your name.

USER: That's ok, no problem. Thank you for checking.

ASSISTANT: Thank you for contacting us.