You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: Alexander Martin here.

ASSISTANT: Ok.

USER: Please book my ticket from CLT to OAK.

ASSISTANT: Sure, will you mention your travelling dates please?

USER: My trip dates are Sept 22 and Sept 24.

ASSISTANT: Do you have any specifications?

USER: I need a connecting flight.

ASSISTANT: Do you have any class preferences?

USER: No, can you search for return flight in the evening?

ASSISTANT: Please give me a moment.

USER: Sure.

ASSISTANT: Thanks for waiting, there is no flights found under your preferable details.

USER: No problem, thank you.

ASSISTANT: Welcome, have a great day.