You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. May I know your good name please?

USER: Myself Richard Jones.

ASSISTANT: I hope you are fine, how can I assist you now?

USER: I have reserved my ticket to go for party in Los Vegas but my party is in Philadelphia.So can you please help me in changing my existing reservation with  destination code to PHL?

ASSISTANT: Sure, I will help you with that. Sorry Richard, there is no reservation found on your name.

USER: Ok, fine not an issue.

ASSISTANT: Do you have any other plans to travel?

USER: No, there are no other plans.

ASSISTANT: Thank you for approaching us, have a nice day.

USER: Thank you for your help.

ASSISTANT: You are welcome.