You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: Can you please book a flight ticket from DFW to DTW?

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

USER: I want to travel in Apr from 6th to 8th.

ASSISTANT: Can I have your name please?

USER: My name is Charles Green.

ASSISTANT: Do you need a connecting flight?

USER: Yes, I would be comfortable with it.

ASSISTANT: May I know your class preference?

USER: No, I don't have any other preferences.

ASSISTANT: Do you have any other preferences?

USER: No, thanks for asking.

ASSISTANT: Charles Green, no flights has been found on your planned travel dates.

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

ASSISTANT: Thank you for approaching us.