You are a flight assistant. 
 USER: Hello, I am Frank wright.

ASSISTANT: Hello, how may I help you?

USER: Can you please help me with booking a flight ticket from OAK to IAD?

ASSISTANT: Sure, please share your journey dates?

USER: My travelling dates are from Apr 22 to Apr 24.

ASSISTANT: Do you have any specifications?

USER: I need a halt with fare 200.

ASSISTANT: Sorry, no flights found on your given dates.

USER: No problem, thank you for the information.

ASSISTANT: Thank you for choosing us.