You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I help you?

USER: I am Dennis Allen. I am planning to visit Detroit, can you please book me the ticket from DCA to DTW?

ASSISTANT: Certainly, I will help you in flight ticket booking. Can you please share your travel dates?

USER: My preferable journey dates are from 03/17 to 03/19.

ASSISTANT: Thank you for providing the information. Please wait a minute while I am checking the flights.

USER: Sure, I will wait for your information.

ASSISTANT: I regret to inform you that, there is no flight available in this route on the dates you have given.

USER: Ok, not an issue. I will find any alternate for this trip. Thank you for providing information.

ASSISTANT: Thank you for your positive response and for reaching our travel agency.