You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I am Christopher Harris. I want to book a ticket from IAD to SFO to meet my parents, can you help me in booking?

ASSISTANT: Will you mention your travelling dates please?

USER: I am departing on 08/28 and return on 08/30. Make sure the connection limit 0.

ASSISTANT: Please give me a moment. There is no flights found under your preferable details.

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

ASSISTANT: Welcome, have a great day.