You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. What help that I can assist you?

USER: I am Melissa Walker here. I want to book a flight ticket from ATL to IAD. Can you make a reservation for me?

ASSISTANT: Sure, I am here to help you in booking.

USER: Thank you.

ASSISTANT: May I know your travel dates?

USER: Sure, my itinerary dates are on  02/16 and back on 02/18.

ASSISTANT: I have based on your details, I am unable to find a flight on your details to reach your destination. Sorry for the trouble.

USER: Ok, not a problem. Thank you for your information.

ASSISTANT: It's my pleasure and thank you for reaching us.