You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Jonathan Hall.

ASSISTANT: How can I  help you?

USER: Can you help me in booking on Aug 15 to Aug 17, as there is a conference meeting to attend?

ASSISTANT: Sure, may I know your airport codes please?

USER: My source is LAX and destination is IAD.

ASSISTANT: I am sorry no flights found on your route.

USER: No issue, thank you.

ASSISTANT: Thank you for choosing us.