You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: Can you aid me to book a flight ticket from IAD to OAK?

ASSISTANT: Sure, can I know your trip dates?

USER: I planned my trip on the dates Apr 3 and Apr 5.

ASSISTANT: Do you have any connection limit?

USER: I am looking for a connecting flight.

ASSISTANT: Do you have any other specifications?

USER: I prefer normal cost airline for my journey.

ASSISTANT: Can I know your good name?

USER: Myself Charles Lewis.

ASSISTANT: Sorry, no flights are available in this route as per your requested dates.

USER: No issue, anyway thank you for checking.

ASSISTANT: Thank you for reaching us.