You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Can you please help me to book a direct flight to reach Washington?

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Can you share me your travelling dates?

USER: My planned dates are on July 30th to Aug 1st.

ASSISTANT: May I know your source point and destination point?

USER: My airport codes are HOU - IAD.

ASSISTANT: Let me know your name?

USER: Sure, my name is Steven Collins.

ASSISTANT: Do you have any other specifications?

USER: No.

ASSISTANT: Ok, wait for some time.

USER: Ok, I will wait.

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

USER: Not a problem, thank you.

ASSISTANT: Thanks for approaching us.