You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you out today?

USER: I need to cancel my reservation which I have done earlier to give guest lecture in famous university but now I am unable to travel so please help me with cancelling my reservation.

ASSISTANT: Sure, I will help you out. Can you please provide me your name?

USER: Thank you. Please check the reservation with the name of Charles Allen.

ASSISTANT: Ok Charles, please wait a moment.

USER: Sure, I will wait for your response.

ASSISTANT: Thank you for your patience. Sorry Charles, there is no reservations found with this name.

USER: Oh! May be booking is not done properly. Anyway, thank you for your time.

ASSISTANT: Thank you for choosing our services Charles. Have a nice day.

USER: Welcome.

ASSISTANT: Most welcome.