You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I aid you?

USER: Can you help me in booking on Jul 17 to Jul 19, as there is a musical concert in Denver?

ASSISTANT: Sure, will you please let me know your airport codes?

USER: My source is IAD and destination is DEN.

ASSISTANT: May I know your airline preference?

USER: I prefer a normal-cost airline.

ASSISTANT: How many connections do you need?

USER: I need a connecting flight.

ASSISTANT: Is there any other requirements?

USER: No.

ASSISTANT: May I know your good name?

USER: I am Dorothy Smith.

ASSISTANT: Ok Dorothy Smith, we regret to inform to you that there are no flights available matching your request.

USER: No issue, thank you.

ASSISTANT: Thank you for consulting us.