You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Daniel Wright.

ASSISTANT: How can I assist you Wright?

USER: I am planning to go IAD, can you please help me in booking my flight ticket?

ASSISTANT: Sure, I will help you. May I know your desired travel dates please?

USER: My trip dates are 05/15 to 05/17.

ASSISTANT: From where you are willing to travel to IAD?

USER: I will fly from HOU.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT: Sorry to say. there is no flight available on your desired travel.

USER: No issue, thank you for checking.

ASSISTANT: Thank you for opting us.