You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I support you today?

USER: I need to go Charlotte for my vacation holidays so please help me with flight ticket booking from DCA to CLT.

ASSISTANT: Sure, please share me your trip dates.

USER: Thank you. I have planned my travel dates as May 10 and May 12.

ASSISTANT: Is there any class preferences for you?

USER: I am ok with any class to travel.

ASSISTANT: May I know your airlines specifications?

USER: I am not specific about any airlines.

ASSISTANT: For booking, we need your good name. Please mention it.

USER: Sure, myself Sandra Taylor.

ASSISTANT: We found a Delta airline and 1011 is flight number with a  fare of 100. Shall I proceed?

USER: As I am looking for direct flight, if it is a direct flight you can proceed with booking.

ASSISTANT: I will verify for direct flight and get back to you.

USER: Sure, I will wait for your response.

ASSISTANT: Sorry to say that, there are no flights available on the routes of your journey.

USER: Oh! It is sad to hear. I will choose another agency this time. Anyway, thank you for your time.

ASSISTANT: Thank you for opting us.

USER: Most welcome.