You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Can you please book me a ticket from LAS to DCA?

ASSISTANT: Sure, I am happy to help you. May I know your travel dates?

USER: My planned dates of journey are Dec 19 and Dec 21.

ASSISTANT: Ok, do you have any specifications?

USER: I prefer normal cost airlines.

ASSISTANT: May I know your name?

USER: My name is Anna Thompson.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I would like to travel in connecting flight.

ASSISTANT: Sorry, there is no flight available as per your requirements.

USER: Ok, not an issue. Thank you for providing information.

ASSISTANT: You are welcome and have a nice day.