You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Melissa Lee.

ASSISTANT: Lee, how may I help you?

USER: Can you please book a flight ticket from DCA to DFW?

ASSISTANT: Please provide your itinerary dates.

USER: Sure, I need to travel on dates of 06/05 and 06/07.

ASSISTANT: Please give me a moment to check for a best flight on your route.

USER: Sure, take your time.

ASSISTANT: UA airlines with flight 1016 is providing service with 1 connection and ticket costs you 300.

USER: No, I need flight ticket with price 200 only.

ASSISTANT: Let me check.

USER: Thank you.

ASSISTANT: Sorry, no flight is available based on your requirements.

USER: Oh! It is sad to hear. Anyway, thank you for your time.

ASSISTANT: Thank you for approaching us.

USER: Most welcome.