You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you at present?

USER: Can you please reserve me a flight ticket from DCA to EWR?

ASSISTANT: Sure, let me know your class preference.

USER: I do not have any class preferences.

ASSISTANT: Ok, let me know your planned dates.

USER: My trip dates are 01/10 - 01/12.

ASSISTANT: May I know your name please?

USER: Carol Brown here.

ASSISTANT: Do you have any other concerns to say?

USER: My depart time should be in the morning.

ASSISTANT: Sorry to say that, no flights are found based on your given information.

USER: No issues, thank you.

ASSISTANT: Thank you for choosing us.