You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Steven Smith.

ASSISTANT: How can I assist you now?

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

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Sorry Steven, there are no flights found on your requested dates.

USER: Ok, no problem.

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

USER: Thanks for your information.

ASSISTANT: You are welcome.