You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I render you today?

USER: Mark Rodriguez here.

ASSISTANT: Ok.

USER: I want to book a flight ticket from DCA to LGA. Could you help me in booking?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: When you are willing to travel?

USER: My preferable dates are from 03/28 to 03/30.

ASSISTANT: Do you have any specifications?

USER: Yes, I need a halt.

ASSISTANT: Ok, please wait for some time.

USER: Ok.

ASSISTANT: Thanks for waiting. Sorry, there are no flights found on your requested dates.

USER: That's ok, no problem. Thank you.

ASSISTANT: Thank you for reaching us, have a good day.