You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: John Williams here.

ASSISTANT: How can I aid you?

USER: I would like to book a ticket from DEN to SEA, can you please help me with that?

ASSISTANT: Sure, may I know your planned travel dates?

USER: The travel dates are from May 28 to May 30.

ASSISTANT: Do you have any specifications?

USER: My depart time is at afternoon.

ASSISTANT: Sorry, there is no flight with your desired intent.

USER: I want a flight with a single connection.

ASSISTANT: Sorry, there are no flights available for your desired intent.

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

ASSISTANT: Thank you for reaching us.