You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Brenda Smith.

ASSISTANT: Brenda Smith, how may I aid you?

USER: I would like to cancel my existing reservation because my trip dates are postponed, can you help me?

ASSISTANT: Sure, please wait for a moment to check our database.

USER: Ok, take your own time.

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

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.