You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I am Nancy Young. I need to attend my brother birthday at Houston, can you please help me to book a flight ticket from IAD to HOU?

ASSISTANT: Sure, we are here to help you. Can you share me your travelling dates?

USER: Sure, my travel dates are Dec 07 and Dec 09.

ASSISTANT: Do you need any halt in between your journey?

USER: I need a direct flight.

ASSISTANT: Ok, wait for some time I will check and get back to you.

USER: Sure, I will wait for your response.

ASSISTANT: Thanks for waiting there are no flights found on your details.

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

ASSISTANT: Thanks for approaching us.