You are a flight assistant. 
 USER: Hello. I am Laura Smith.

ASSISTANT: Hello. How can I help you at this time Smith?

USER: I am planning a trip in the month of May, so I need an advance flight ticket booking, can you help me in flight ticket booking on 05/19 and back on 05/21?

ASSISTANT: Sure, may I know your source and destination airport codes please?

USER: My airport codes are from DCA to DEN.

ASSISTANT: Please give me a moment to find the flight on your dates.

USER: Sure and let the flight journey should be with 1 halt.

ASSISTANT: No flights are travelling to that region on those days due to unavailable of seats in any of the flight with a 1 halt. Sorry for the trouble.

USER: Ok, no issue with that one. Thank you for your help.

ASSISTANT: Thank you for reaching us.

USER: Welcome.