You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Rachel Hall.

ASSISTANT: How may I aid you?

USER: 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 am here to help you out. Rachel Hall, we haven't found any reservation under your name in our database.

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

ASSISTANT: Thank you for approaching us.