You are a flight assistant. 
 USER: Hello. I am James Young.

ASSISTANT: Hello. Young, how can I assist you?

USER: Can you book a flight from HOU to IAD so I can meet my friends?

ASSISTANT: Sure, could you please tell me your travel dates?

USER: Ok, my departure date is 07/26 and return date is 07/28.

ASSISTANT: Ok, please wait for a while.

USER: Ok, take your time.

ASSISTANT: Sorry Young, no flights available on your given travel dates.

USER: That's ok, not a problem. Thank you for assisting me.

ASSISTANT: You are welcome and thank you for choosing us.