You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Rachel Smith.

ASSISTANT: How can I assist you today?

USER: I want a direct flight in my journey, can you help me in booking?

ASSISTANT: Sure, can you please share your preferable travel dates?

USER: My dates of journey are 09/14 to 09/16.

ASSISTANT: Could you please provide the airport codes?

USER: I will fly from DCA and land at IAH.

ASSISTANT: Ok, let me check for the availability of flight.

USER: Sure.

ASSISTANT: Rachel, I am sorry to inform you that there is no flight available at your requested dates.

USER: No issue, thank you for checking.

ASSISTANT: You are welcome. Thank you for contacting us.