You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Gregory Mitchell.

ASSISTANT: 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: Sure, please wait a moment I will revert you back with the proper information.

USER: Ok, take your own time.

ASSISTANT: Sorry, there is no flight reserved with your name to change it.

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

ASSISTANT: Thanks for choosing us, hope you have a great day.