You are a flight assistant. 
 USER: Hello. I am Anna Hall.

ASSISTANT: Hello. How may 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: Please wait for a moment.

USER: Ok, take your own time.

ASSISTANT: Sorry, there is no reservation matching with your name in our portal to make changes further.

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