You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How may I render you today?

USER: I am Rebecca Hernandez.

ASSISTANT: Ok.

USER: Please, help me in cancelling my reservation.

ASSISTANT: Sure.

USER: Thank you.

ASSISTANT: Please wait for a while, I will revert to you.

USER: Sure.

ASSISTANT: Thanks for waiting.

USER: Ok.

ASSISTANT: But we are sorry to inform you that, no reservation is existed previously to proceed further.

USER: Ok, thak you for  information.

ASSISTANT: Thank you.