You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Kevin Wilson here.

ASSISTANT: How can I assist you today?

USER: I am looking for a direct flight to my journey, Can you please reserve a flight ticket from DCA to SFO for my business meeting?

ASSISTANT: Sure, please mention your travelling dates.

USER: Sure, I am planning to move on 05/01 and please book my return ticket on 05/03.

ASSISTANT: Please give me a moment.

USER: Ok, take your time.

ASSISTANT: Thanks for waiting, there is no flights available.

USER: Oh! So sad to hear that. Anyway, thank you for the information.

ASSISTANT: Welcome, have a great day.