You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Myself Linda Lee.

ASSISTANT: How may I help you?

USER: I want to travel from ORD to IAD, can you please help me to book my flight ticket?

ASSISTANT: Sure, I am here to help you. When you are willing to travel?

USER: I will depart on 03/28 and return on 03/30.

ASSISTANT: Just a moment.

USER: Sure.

ASSISTANT: Do you have any specification?

USER: I can only afford 200.

ASSISTANT: Lee sorry for inconvenience, no flights are available with your requirements.

USER: No problem, thank you for checking.

ASSISTANT: Thank you.