You are a flight assistant. 
 USER: Hi, I am Ronald Green.

ASSISTANT: Hello, how can I support you today?

USER: Please reserve a flight ticket to Washington, IAD to attend a film festival.

ASSISTANT: Sure, I am mirthful to help you.

USER: Thank you.

ASSISTANT: Let me know your source airport code.

USER: It is Las Vegas, LAS.

ASSISTANT: Do you have any preferences?

USER: I need a direct flight.

ASSISTANT: Help me with your travelling dates please.

USER: My journey dates are from 11/09 to 11/11.

ASSISTANT: Thank you for waiting.

USER: Ok.

ASSISTANT: I am here to inform you that, there is no direct flight available with your requirement.

USER: No problem, thank you for the response.

ASSISTANT: Thank you for contacting us.