You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Robert Collins.

ASSISTANT: How may I oblige you today?

USER: I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, I will help you to change your reservation.

USER: Thank you.

ASSISTANT: Please hold on a minute, I will get back to you with the status of your reservation.

USER: Sure.

ASSISTANT: Thanks for waiting. We hardly tried to change your reservation, but no reservation found on your name.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for opting us.