You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: My name is Thomas Scott. I have a plan to meet my brother in Denver, can you help me for booking?

ASSISTANT: Sure, I am here to help you out. Please provide me your location airport codes.

USER: My travelling airport codes are from DCA to DEN.

ASSISTANT: Share me your trip dates?

USER: My travelling dates are from 09/13 till 09/15.

ASSISTANT: Sorry Scott, no flights are available in your route.

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

ASSISTANT: Thank you for reaching us.

USER: Welcome.