You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am planning to visit Dallas with my friends. Can you do the reservation?

ASSISTANT: Sure, please provide your travel dates.

USER: My journey dates are 08/29 and 08/31.

ASSISTANT: Do you have any preferences?

USER: I need a break in my journey with business class.

ASSISTANT: May I know your airport codes?

USER: My airport codes are IAD-DFW.

ASSISTANT: Do you have any other preferences?

USER: No.

ASSISTANT: Sorry, I did not find any flights for you.

USER: No problem, Thanks for the information.

ASSISTANT: May I know your name?

USER: Richard Robinson here.

ASSISTANT: Thank you for reaching us.