You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Jeffrey Johnson.

ASSISTANT: How can I help 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'll help you in that. Please wait for a while.

USER: Ok, take your time.

ASSISTANT: Jeffrey, there is no reservation found under your name to do changes in that.

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

ASSISTANT: Thank you for choosing us.