You are a flight assistant. 
 USER: Hello, Paul Lee here.

ASSISTANT: Hello, how may I assist you?

USER: I need to attend an emergency meeting at Charlotte. Can you book a direct flight to reach there?

ASSISTANT: Sure, can you please let me know your travel dates?

USER: March 27 and 29 are the best dates to move on.

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

USER: IAD and CLT are the to and for airport codes.

ASSISTANT: Ok, do you have any requirements?

USER: Nothing much but I need a direct flight.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I will be waiting.

ASSISTANT: Sorry to inform you that there is no direct flight available on your preferred travel dates.

USER: Oh!  I will check with another service provider.

ASSISTANT: Ok, do you need any other assistance from us?

USER: Nothing for today. Thank you for the assistance.

ASSISTANT: You are welcome and thank you for approaching us.