You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, How can I serve you?

USER: Due to a sudden meeting at office with my client on my boarding day, I want to change an  recent reservation. Can you please help me in that?

ASSISTANT: Sure, May I know your name?

USER: My name is Helen Thomas.

ASSISTANT: Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name. Thank you for reaching us.

USER: Ok, no worries. Thank you.