You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I want to cancel my reservation, due to some problems I am unable to travel those dates so can you help me with that?

ASSISTANT: Sure, may I know your good name please?

USER: Sure, my name is Larry Collins.

ASSISTANT: There is no reservation found under your name to do changes in that.

USER: Oh! It's ok no problem, may be I am not booked my ticket properly at that time. Thank you for your service.

ASSISTANT: Thank you for choosing us.