You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: Can you help me to book a flight ticket from JFK to DCA?

ASSISTANT: Sure, when are you willing to travel?

USER: I want to fly on 29 Apr and return on May 01.

ASSISTANT: Do you have any preferences?

USER: I would like to depart in the afternoon and return in the evening.

ASSISTANT: May I know your name please?

USER: I am Emma Hernandez.

ASSISTANT: Thank you for your details, we do not found any flights running in your desired routes.

USER: It's ok, not a problem, thank you.

ASSISTANT: Thank you for reaching us.