You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Gary Collins.

ASSISTANT: How can I assist you at this moment?

USER: I want to travel from DCA to IAH. Can you book a flight ticket for me?

ASSISTANT: Sure Gary Collins, I will help you with that. Can I have your travel dates please?

USER: I want to fly on 02/17 and 02/19.

ASSISTANT: Ok, please wait a moment to check flight availability.

USER: Ok, take your time.

ASSISTANT: Sorry Gary Collins, no flight is available to you on your dates.

USER: That's ok.

ASSISTANT: Thank you for choosing us, have a good day.

USER: Anyways, thank you for your help.