You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: David Smith here.

ASSISTANT: Welcome to DDY agency. How can I assist you today?

USER: My plan to visit a function is postponed as of now, I want to cancel my recent reservation.

ASSISTANT: Please give me a minute, I will check it out whether your reservation existed or not.

USER: Sure ok.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: That's ok, thank you for your help.

ASSISTANT: Thank you for reaching us, I hope our agency will serve you in the future.

USER: Thank you for your help.