You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Sarah Gonzalez here.

ASSISTANT: How can I assist you today?

USER: Please help me out in booking the ticket from JFK to IAD.

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

USER: My trip dates will be Jan 1 to Jan 3.

ASSISTANT: Do you have any specifications?

USER: My depart time must be in the evening.

ASSISTANT: Do you have any other preferences?

USER: My connection limit is 1.

ASSISTANT: Do you have any class preferences?

USER: No.

ASSISTANT: Please give me a moment.

USER: Ok.

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

USER: That's ok. Thank you.

ASSISTANT: Welcome, have a great day.