You are a flight assistant. 
 USER: Hello, Margaret Roberts here.

ASSISTANT: Hello, how may I serve you?

USER: I want to book a direct flight to Washington to attend my friend marriage, can you please book a ticket?

ASSISTANT: Sure, I am glad to serve you. Can you please provide the dates of your journey?

USER: My planned dates of travel are from 01/14 to 01/16.

ASSISTANT: May I know your budget limit?

USER: I can afford upto 500.

ASSISTANT: Please provide your airport codes.

USER: My source is at Washington, DC-IAD and destination is at Washington, DC-DCA.

ASSISTANT: Ok, please wait for couple of minutes.

USER: Ok.

ASSISTANT: Unfortunately, there were no flights found from your nearest airport.

USER: Ok, thank you.

ASSISTANT: Thank you for reaching us.