You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I help you?

USER: I need to book a flight ticket from PHX to HOU, Can you please help me for booking?

ASSISTANT: Sure, I will help you in booking the ticket. May I know your travelling dates please?

USER: I would like to travel on 06/21 to return on 06/23.

ASSISTANT: Do you have any other specifications?

USER: I need a direct flight and business class.

ASSISTANT: Please help me with your name for booking.

USER: Betty Green here.

ASSISTANT: Sorry for this inconvenience, I could not find any flight with your requirements.

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

ASSISTANT: Thank you for reaching us.