You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Carol Thomas.

ASSISTANT: How can I aid you today?

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

ASSISTANT: I am here to help you with that. Sorry Carol, there is no reservation found under your name in our database.

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

ASSISTANT: Thank you for reaching us.