You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I am Larry Carter. I am planning to travel from DFW to DEN, can you help in booking  a flight for me?

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

USER: My travelling dates are 07/18 to 07/20.

ASSISTANT: Ok, please be on hold for a while.

USER: Sure.

ASSISTANT: Sorry, there is no flight available as per your given dates.

USER: That's ok, thank you for your help.

ASSISTANT: You are welcome and thank you for choosing us.