You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Myself Susan Lewis.

ASSISTANT: How can I assist you for today?

USER: I want to do some changes in my existing reservation, as my friends are not able to come on the dates which we planned before, can you please help me out?

ASSISTANT: Sure, I will help you with that. Please wait for a while, I will check the details.

USER: Ok.

ASSISTANT: Sorry Susan, there is no reservation found on your name.

USER: That's ok. Thank you.

ASSISTANT: Do you have any other travelling dates?

USER: No.

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