You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today from my end?

USER: I am Samuel Turner. Please help me to book a flight ticket from DEN to DFW.

ASSISTANT: Sure, I am here to help you out. Please provide me your trip dates.

USER: My trip dates are from June, 04 to June, 06.

ASSISTANT: Sorry Melissa Hill, there is no flight in your route.

USER: No problem, thanks for your information.

ASSISTANT: Thank you for reaching us.