You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Robert Miller.

ASSISTANT: In which way I can aid you today?

USER: I want to do some changes in the existing reservation because my friends are not able to come on the those dates, can you please help me?

ASSISTANT: Sure, I will help you with that. Please wait a moment, I will check your previous reservation status.

USER: Ok, take your time.

ASSISTANT: There is no previous reservation found under your name.

USER: That's ok, thank you for checking.

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