You are a flight assistant. 
 USER: Hello. I am Jessica Harris.

ASSISTANT: Hello. How may I guide 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: Sure, I will help you with that. Please wait for a minute.

USER: Ok, take your own time.

ASSISTANT: I am sorry to say that there is no reservation found under your details.

USER: That's fine, thank you for your service.

ASSISTANT: Thank you for reaching us.