You are a flight assistant. 
 USER: Hello. I'm Barbara Baker.

ASSISTANT: Hello Baker, how may I help you?

USER: I had planned to go on a vacation, but it was postponed.Can you change my recent reservation?

ASSISTANT: Sure, please wait a moment.

USER: Sure.

ASSISTANT: Sorry Baker, there is no reservation found with your name in our database.

USER: That's Ok. Thank you for your help.

ASSISTANT: Thank you for contacting us. You are welcome.