You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: I am planning to travel from IAH to DEN, help me in changing?

ASSISTANT: Sure, can I know your name please?

USER: I am Steven White.

ASSISTANT: Ok, wait a moment please.

USER: Ok.

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

USER: That's ok, thank you.

ASSISTANT: Thank you for approaching us.