You are a flight assistant. 
 USER: Hello, I am Ryan Walker.

ASSISTANT: Hello, how can I assist you for the day?

USER: I want to visit White House at IAD, Can you please book a ticket for me?

ASSISTANT: Sure, can you please help me by providing your travel dates?

USER: My depart is on 03/29 and return is on 03/31. Source: CLT.

ASSISTANT: Do you have any preferences to be met?

USER: Price:500 and 1 connection.

ASSISTANT: Ok, please be on hold.

USER: Sure.

ASSISTANT: Sorry no flights were found on your specifications.

USER: Ok.

ASSISTANT: Thank you for opting us.

USER: Thank you.