You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Andrew Lopez.

ASSISTANT: How can I assist you at this moment?

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 will help you with this.

USER: Ok.

ASSISTANT: Andrew Lopez, there is no active reservation found under your name in our database.

USER: That's ok.

ASSISTANT: Thank you for utilising our service.

USER: Anyways, thank you for your help.