You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am planning to attend a Tennis competition in Houston IAH from IAD. Can you make a reservation for me?

ASSISTANT: Sure, I am glad to help you in booking. Can you please share your travel dates?

USER: Thank you, my planned trip dates are on July 24 and return on July 26.

ASSISTANT: Ok, please share your name.

USER: Yes, I am Mary Mitchell.

ASSISTANT: Let me know your connection limit.

USER: I need a single connecting flight.

ASSISTANT: Which class do you prefer?

USER: I want to return in the evening time.

ASSISTANT: Do you have any specification?

USER: No, thanks for asking.

ASSISTANT: Sorry, no flights are available on your preferable travel dates.

USER: Ok, not an problem. Thank you for your help.

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