You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: My name is Robert Parker. I am planning to book a flight ticket from LAS to IAD, can you please help me for booking?

ASSISTANT: Can you please share with us your travelling dates?

USER: My travelling dates are from 01/29 till 01/31.

ASSISTANT: Please wait a moment. Sorry, no flights are available with your requirement.

USER: That's ok, thank you for checking.

ASSISTANT: Do you have any other dates to travel?

USER: No.

ASSISTANT: Thank you for approaching us.

USER: Welcome.