You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is Alexander Williams. I would like to travel from JFK to LAS, could you help me out?

ASSISTANT: Sure, please share your travel dates.

USER: My preferable dates are from 04/22 to 04/24.

ASSISTANT: Sorry, no flights available for the given schedule.

USER: That's ok.

ASSISTANT: Thank you for reaching us.

USER: Thank you for your help.