You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: I am Emily Brown, planning to go for technical tour to NASA space center at Houston, HOU. Can you book a flight ticket on 05/01?

ASSISTANT: Sure, please help me with your return date?

USER: I would like to return on 05/03.

ASSISTANT: Ok, let me know your departure airport code?

USER: Washington, IAD is my source point.

ASSISTANT: Ok, please hold on a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, no flights found with your requested details.

USER: It's ok, thank you for your information.

ASSISTANT: Thank you for connecting with us.