You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Carol Williams. I had planned to go on a trip, but it was postponed due to some reasons. Can you change my recent reservation?

ASSISTANT: Sure, I will help you. Let me check your reservation status in our database.

USER: Ok, take your time.

ASSISTANT: Williams, sorry for inconvenience, no reservation is found on your name in our records.

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

ASSISTANT: You are welcome.