You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you at this moment?

USER: Can you avail me to book a flight from IAD to HOU?

ASSISTANT: Sure, I am  happy to help you with that. Can I have your travel  dates please?

USER: My travel dates are May 15 and 17.

ASSISTANT: Ok,  please let me know your  preferable timings of your journey.

USER: I am comfortable with any time.

ASSISTANT: Do you have any other specifications?

USER: I need a break in my journey.

ASSISTANT: Can I have your good name please?

USER: Helen Young here.

ASSISTANT: Sorry to inform you that  no flight is available to you on your planned dates.

USER: Ok, thank you.

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